--- /dev/null
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
--- /dev/null
+Directory overview:
+==================
+
+mtl/ Mini Template Library
+core/ A core version of the solver
+simp/ An extended solver with simplification capabilities
+README
+LICENSE
+
+To build (release version: without assertions, statically linked, etc):
+======================================================================
+
+cd { core | simp }
+gmake rs
+
+Usage:
+======
+
+TODO
--- /dev/null
+/******************************************************************************************[Main.C]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include <ctime>
+#include <cstring>
+#include <stdint.h>
+#include <errno.h>
+
+#include <signal.h>
+#include <zlib.h>
+
+#include "Solver.h"
+
+/*************************************************************************************/
+#ifdef _MSC_VER
+#include <ctime>
+
+static inline double cpuTime(void) {
+ return (double)clock() / CLOCKS_PER_SEC; }
+#else
+
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <unistd.h>
+
+static inline double cpuTime(void) {
+ struct rusage ru;
+ getrusage(RUSAGE_SELF, &ru);
+ return (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000; }
+#endif
+
+
+#if defined(__linux__)
+static inline int memReadStat(int field)
+{
+ char name[256];
+ pid_t pid = getpid();
+ sprintf(name, "/proc/%d/statm", pid);
+ FILE* in = fopen(name, "rb");
+ if (in == NULL) return 0;
+ int value;
+ for (; field >= 0; field--)
+ fscanf(in, "%d", &value);
+ fclose(in);
+ return value;
+}
+static inline uint64_t memUsed() { return (uint64_t)memReadStat(0) * (uint64_t)getpagesize(); }
+
+
+#elif defined(__FreeBSD__)
+static inline uint64_t memUsed(void) {
+ struct rusage ru;
+ getrusage(RUSAGE_SELF, &ru);
+ return ru.ru_maxrss*1024; }
+
+
+#else
+static inline uint64_t memUsed() { return 0; }
+#endif
+
+#if defined(__linux__)
+#include <fpu_control.h>
+#endif
+
+//=================================================================================================
+// DIMACS Parser:
+
+#define CHUNK_LIMIT 1048576
+
+class StreamBuffer {
+ gzFile in;
+ char buf[CHUNK_LIMIT];
+ int pos;
+ int size;
+
+ void assureLookahead() {
+ if (pos >= size) {
+ pos = 0;
+ size = gzread(in, buf, sizeof(buf)); } }
+
+public:
+ StreamBuffer(gzFile i) : in(i), pos(0), size(0) {
+ assureLookahead(); }
+
+ int operator * () { return (pos >= size) ? EOF : buf[pos]; }
+ void operator ++ () { pos++; assureLookahead(); }
+};
+
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+template<class B>
+static void skipWhitespace(B& in) {
+ while ((*in >= 9 && *in <= 13) || *in == 32)
+ ++in; }
+
+template<class B>
+static void skipLine(B& in) {
+ for (;;){
+ if (*in == EOF || *in == '\0') return;
+ if (*in == '\n') { ++in; return; }
+ ++in; } }
+
+template<class B>
+static int parseInt(B& in) {
+ int val = 0;
+ bool neg = false;
+ skipWhitespace(in);
+ if (*in == '-') neg = true, ++in;
+ else if (*in == '+') ++in;
+ if (*in < '0' || *in > '9') reportf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+ while (*in >= '0' && *in <= '9')
+ val = val*10 + (*in - '0'),
+ ++in;
+ return neg ? -val : val; }
+
+template<class B>
+static void readClause(B& in, Solver& S, vec<Lit>& lits) {
+ int parsed_lit, var;
+ lits.clear();
+ for (;;){
+ parsed_lit = parseInt(in);
+ if (parsed_lit == 0) break;
+ var = abs(parsed_lit)-1;
+ while (var >= S.nVars()) S.newVar();
+ lits.push( (parsed_lit > 0) ? Lit(var) : ~Lit(var) );
+ }
+}
+
+template<class B>
+static bool match(B& in, char* str) {
+ for (; *str != 0; ++str, ++in)
+ if (*str != *in)
+ return false;
+ return true;
+}
+
+
+template<class B>
+static void parse_DIMACS_main(B& in, Solver& S) {
+ vec<Lit> lits;
+ for (;;){
+ skipWhitespace(in);
+ if (*in == EOF)
+ break;
+ else if (*in == 'p'){
+ if (match(in, "p cnf")){
+ int vars = parseInt(in);
+ int clauses = parseInt(in);
+ reportf("| Number of variables: %-12d |\n", vars);
+ reportf("| Number of clauses: %-12d |\n", clauses);
+ }else{
+ reportf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+ }
+ } else if (*in == 'c' || *in == 'p')
+ skipLine(in);
+ else
+ readClause(in, S, lits),
+ S.addClause(lits);
+ }
+}
+
+// Inserts problem into solver.
+//
+static void parse_DIMACS(gzFile input_stream, Solver& S) {
+ StreamBuffer in(input_stream);
+ parse_DIMACS_main(in, S); }
+
+
+//=================================================================================================
+
+
+void printStats(Solver& solver)
+{
+ double cpu_time = cpuTime();
+ uint64_t mem_used = memUsed();
+ reportf("restarts : %lld\n", solver.starts);
+ reportf("conflicts : %-12lld (%.0f /sec)\n", solver.conflicts , solver.conflicts /cpu_time);
+ reportf("decisions : %-12lld (%4.2f %% random) (%.0f /sec)\n", solver.decisions, (float)solver.rnd_decisions*100 / (float)solver.decisions, solver.decisions /cpu_time);
+ reportf("propagations : %-12lld (%.0f /sec)\n", solver.propagations, solver.propagations/cpu_time);
+ reportf("conflict literals : %-12lld (%4.2f %% deleted)\n", solver.tot_literals, (solver.max_literals - solver.tot_literals)*100 / (double)solver.max_literals);
+ if (mem_used != 0) reportf("Memory used : %.2f MB\n", mem_used / 1048576.0);
+ reportf("CPU time : %g s\n", cpu_time);
+}
+
+Solver* solver;
+static void SIGINT_handler(int signum) {
+ reportf("\n"); reportf("*** INTERRUPTED ***\n");
+ printStats(*solver);
+ reportf("\n"); reportf("*** INTERRUPTED ***\n");
+ exit(1); }
+
+
+//=================================================================================================
+// Main:
+
+void printUsage(char** argv)
+{
+ reportf("USAGE: %s [options] <input-file> <result-output-file>\n\n where input may be either in plain or gzipped DIMACS.\n\n", argv[0]);
+ reportf("OPTIONS:\n\n");
+ reportf(" -polarity-mode = {true,false,rnd}\n");
+ reportf(" -decay = <num> [ 0 - 1 ]\n");
+ reportf(" -rnd-freq = <num> [ 0 - 1 ]\n");
+ reportf(" -verbosity = {0,1,2}\n");
+ reportf("\n");
+}
+
+
+const char* hasPrefix(const char* str, const char* prefix)
+{
+ int len = strlen(prefix);
+ if (strncmp(str, prefix, len) == 0)
+ return str + len;
+ else
+ return NULL;
+}
+
+
+int main(int argc, char** argv)
+{
+ Solver S;
+ S.verbosity = 1;
+
+
+ int i, j;
+ const char* value;
+ for (i = j = 0; i < argc; i++){
+ if ((value = hasPrefix(argv[i], "-polarity-mode="))){
+ if (strcmp(value, "true") == 0)
+ S.polarity_mode = Solver::polarity_true;
+ else if (strcmp(value, "false") == 0)
+ S.polarity_mode = Solver::polarity_false;
+ else if (strcmp(value, "rnd") == 0)
+ S.polarity_mode = Solver::polarity_rnd;
+ else{
+ reportf("ERROR! unknown polarity-mode %s\n", value);
+ exit(0); }
+
+ }else if ((value = hasPrefix(argv[i], "-rnd-freq="))){
+ double rnd;
+ if (sscanf(value, "%lf", &rnd) <= 0 || rnd < 0 || rnd > 1){
+ reportf("ERROR! illegal rnd-freq constant %s\n", value);
+ exit(0); }
+ S.random_var_freq = rnd;
+
+ }else if ((value = hasPrefix(argv[i], "-decay="))){
+ double decay;
+ if (sscanf(value, "%lf", &decay) <= 0 || decay <= 0 || decay > 1){
+ reportf("ERROR! illegal decay constant %s\n", value);
+ exit(0); }
+ S.var_decay = 1 / decay;
+
+ }else if ((value = hasPrefix(argv[i], "-verbosity="))){
+ int verbosity = (int)strtol(value, NULL, 10);
+ if (verbosity == 0 && errno == EINVAL){
+ reportf("ERROR! illegal verbosity level %s\n", value);
+ exit(0); }
+ S.verbosity = verbosity;
+
+ }else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "-help") == 0 || strcmp(argv[i], "--help") == 0){
+ printUsage(argv);
+ exit(0);
+
+ }else if (strncmp(argv[i], "-", 1) == 0){
+ reportf("ERROR! unknown flag %s\n", argv[i]);
+ exit(0);
+
+ }else
+ argv[j++] = argv[i];
+ }
+ argc = j;
+
+
+ reportf("This is MiniSat 2.0 beta\n");
+#if defined(__linux__)
+ fpu_control_t oldcw, newcw;
+ _FPU_GETCW(oldcw); newcw = (oldcw & ~_FPU_EXTENDED) | _FPU_DOUBLE; _FPU_SETCW(newcw);
+ reportf("WARNING: for repeatability, setting FPU to use double precision\n");
+#endif
+ double cpu_time = cpuTime();
+
+ solver = &S;
+ signal(SIGINT,SIGINT_handler);
+ signal(SIGHUP,SIGINT_handler);
+
+ if (argc == 1)
+ reportf("Reading from standard input... Use '-h' or '--help' for help.\n");
+
+ gzFile in = (argc == 1) ? gzdopen(0, "rb") : gzopen(argv[1], "rb");
+ if (in == NULL)
+ reportf("ERROR! Could not open file: %s\n", argc == 1 ? "<stdin>" : argv[1]), exit(1);
+
+ reportf("============================[ Problem Statistics ]=============================\n");
+ reportf("| |\n");
+
+ parse_DIMACS(in, S);
+ gzclose(in);
+ FILE* res = (argc >= 3) ? fopen(argv[2], "wb") : NULL;
+
+ double parse_time = cpuTime() - cpu_time;
+ reportf("| Parsing time: %-12.2f s |\n", parse_time);
+
+ if (!S.simplify()){
+ reportf("Solved by unit propagation\n");
+ if (res != NULL) fprintf(res, "UNSAT\n"), fclose(res);
+ printf("UNSATISFIABLE\n");
+ exit(20);
+ }
+
+ bool ret = S.solve();
+ printStats(S);
+ reportf("\n");
+ printf(ret ? "SATISFIABLE\n" : "UNSATISFIABLE\n");
+ if (res != NULL){
+ if (ret){
+ fprintf(res, "SAT\n");
+ for (int i = 0; i < S.nVars(); i++)
+ if (S.model[i] != l_Undef)
+ fprintf(res, "%s%s%d", (i==0)?"":" ", (S.model[i]==l_True)?"":"-", i+1);
+ fprintf(res, " 0\n");
+ }else
+ fprintf(res, "UNSAT\n");
+ fclose(res);
+ }
+
+#ifdef NDEBUG
+ exit(ret ? 10 : 20); // (faster than "return", which will invoke the destructor for 'Solver')
+#endif
+}
--- /dev/null
+MTL = ../mtl
+CHDRS = $(wildcard *.h) $(wildcard $(MTL)/*.h)
+EXEC = minisat
+CFLAGS = -I$(MTL) -Wall -ffloat-store
+LFLAGS = -lz
+
+include ../mtl/template.mk
--- /dev/null
+/****************************************************************************************[Solver.C]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include "Solver.h"
+#include "Sort.h"
+#include <cmath>
+
+
+//=================================================================================================
+// Constructor/Destructor:
+
+
+Solver::Solver() :
+
+ // Parameters: (formerly in 'SearchParams')
+ var_decay(1 / 0.95), clause_decay(1 / 0.999), random_var_freq(0.02)
+ , restart_first(100), restart_inc(1.5), learntsize_factor((double)1/(double)3), learntsize_inc(1.1)
+
+ // More parameters:
+ //
+ , expensive_ccmin (true)
+ , polarity_mode (polarity_false)
+ , verbosity (0)
+
+ // Statistics: (formerly in 'SolverStats')
+ //
+ , starts(0), decisions(0), rnd_decisions(0), propagations(0), conflicts(0)
+ , clauses_literals(0), learnts_literals(0), max_literals(0), tot_literals(0)
+
+ , ok (true)
+ , cla_inc (1)
+ , var_inc (1)
+ , qhead (0)
+ , simpDB_assigns (-1)
+ , simpDB_props (0)
+ , order_heap (VarOrderLt(activity))
+ , random_seed (91648253)
+ , progress_estimate(0)
+ , remove_satisfied (true)
+{}
+
+
+Solver::~Solver()
+{
+ for (int i = 0; i < learnts.size(); i++) free(learnts[i]);
+ for (int i = 0; i < clauses.size(); i++) free(clauses[i]);
+}
+
+
+//=================================================================================================
+// Minor methods:
+
+
+// Creates a new SAT variable in the solver. If 'decision_var' is cleared, variable will not be
+// used as a decision variable (NOTE! This has effects on the meaning of a SATISFIABLE result).
+//
+Var Solver::newVar(bool sign, bool dvar)
+{
+ int v = nVars();
+ watches .push(); // (list for positive literal)
+ watches .push(); // (list for negative literal)
+ reason .push(NULL);
+ assigns .push(toInt(l_Undef));
+ level .push(-1);
+ activity .push(0);
+ seen .push(0);
+
+ polarity .push((char)sign);
+ decision_var.push((char)dvar);
+
+ insertVarOrder(v);
+ return v;
+}
+
+
+bool Solver::addClause(vec<Lit>& ps)
+{
+ assert(decisionLevel() == 0);
+
+ if (!ok)
+ return false;
+ else{
+ // Check if clause is satisfied and remove false/duplicate literals:
+ sort(ps);
+ Lit p; int i, j;
+ for (i = j = 0, p = lit_Undef; i < ps.size(); i++)
+ if (value(ps[i]) == l_True || ps[i] == ~p)
+ return true;
+ else if (value(ps[i]) != l_False && ps[i] != p)
+ ps[j++] = p = ps[i];
+ ps.shrink(i - j);
+ }
+
+ if (ps.size() == 0)
+ return ok = false;
+ else if (ps.size() == 1){
+ assert(value(ps[0]) == l_Undef);
+ uncheckedEnqueue(ps[0]);
+ return ok = (propagate() == NULL);
+ }else{
+ Clause* c = Clause_new(ps, false);
+ clauses.push(c);
+ attachClause(*c);
+ }
+
+ return true;
+}
+
+
+void Solver::attachClause(Clause& c) {
+ assert(c.size() > 1);
+ watches[toInt(~c[0])].push(&c);
+ watches[toInt(~c[1])].push(&c);
+ if (c.learnt()) learnts_literals += c.size();
+ else clauses_literals += c.size(); }
+
+
+void Solver::detachClause(Clause& c) {
+ assert(c.size() > 1);
+ assert(find(watches[toInt(~c[0])], &c));
+ assert(find(watches[toInt(~c[1])], &c));
+ remove(watches[toInt(~c[0])], &c);
+ remove(watches[toInt(~c[1])], &c);
+ if (c.learnt()) learnts_literals -= c.size();
+ else clauses_literals -= c.size(); }
+
+
+void Solver::removeClause(Clause& c) {
+ detachClause(c);
+ free(&c); }
+
+
+bool Solver::satisfied(const Clause& c) const {
+ for (int i = 0; i < c.size(); i++)
+ if (value(c[i]) == l_True)
+ return true;
+ return false; }
+
+
+// Revert to the state at given level (keeping all assignment at 'level' but not beyond).
+//
+void Solver::cancelUntil(int level) {
+ if (decisionLevel() > level){
+ for (int c = trail.size()-1; c >= trail_lim[level]; c--){
+ Var x = var(trail[c]);
+ assigns[x] = toInt(l_Undef);
+ insertVarOrder(x); }
+ qhead = trail_lim[level];
+ trail.shrink(trail.size() - trail_lim[level]);
+ trail_lim.shrink(trail_lim.size() - level);
+ } }
+
+
+//=================================================================================================
+// Major methods:
+
+
+Lit Solver::pickBranchLit(int polarity_mode, double random_var_freq)
+{
+ Var next = var_Undef;
+
+ // Random decision:
+ if (drand(random_seed) < random_var_freq && !order_heap.empty()){
+ next = order_heap[irand(random_seed,order_heap.size())];
+ if (toLbool(assigns[next]) == l_Undef && decision_var[next])
+ rnd_decisions++; }
+
+ // Activity based decision:
+ while (next == var_Undef || toLbool(assigns[next]) != l_Undef || !decision_var[next])
+ if (order_heap.empty()){
+ next = var_Undef;
+ break;
+ }else
+ next = order_heap.removeMin();
+
+ bool sign = false;
+ switch (polarity_mode){
+ case polarity_true: sign = false; break;
+ case polarity_false: sign = true; break;
+ case polarity_user: sign = polarity[next]; break;
+ case polarity_rnd: sign = irand(random_seed, 2); break;
+ default: assert(false); }
+
+ return next == var_Undef ? lit_Undef : Lit(next, sign);
+}
+
+
+/*_________________________________________________________________________________________________
+|
+| analyze : (confl : Clause*) (out_learnt : vec<Lit>&) (out_btlevel : int&) -> [void]
+|
+| Description:
+| Analyze conflict and produce a reason clause.
+|
+| Pre-conditions:
+| * 'out_learnt' is assumed to be cleared.
+| * Current decision level must be greater than root level.
+|
+| Post-conditions:
+| * 'out_learnt[0]' is the asserting literal at level 'out_btlevel'.
+|
+| Effect:
+| Will undo part of the trail, upto but not beyond the assumption of the current decision level.
+|________________________________________________________________________________________________@*/
+void Solver::analyze(Clause* confl, vec<Lit>& out_learnt, int& out_btlevel)
+{
+ int pathC = 0;
+ Lit p = lit_Undef;
+
+ // Generate conflict clause:
+ //
+ out_learnt.push(); // (leave room for the asserting literal)
+ int index = trail.size() - 1;
+ out_btlevel = 0;
+
+ do{
+ assert(confl != NULL); // (otherwise should be UIP)
+ Clause& c = *confl;
+
+ if (c.learnt())
+ claBumpActivity(c);
+
+ for (int j = (p == lit_Undef) ? 0 : 1; j < c.size(); j++){
+ Lit q = c[j];
+
+ if (!seen[var(q)] && level[var(q)] > 0){
+ varBumpActivity(var(q));
+ seen[var(q)] = 1;
+ if (level[var(q)] >= decisionLevel())
+ pathC++;
+ else{
+ out_learnt.push(q);
+ if (level[var(q)] > out_btlevel)
+ out_btlevel = level[var(q)];
+ }
+ }
+ }
+
+ // Select next clause to look at:
+ while (!seen[var(trail[index--])]);
+ p = trail[index+1];
+ confl = reason[var(p)];
+ seen[var(p)] = 0;
+ pathC--;
+
+ }while (pathC > 0);
+ out_learnt[0] = ~p;
+
+ // Simplify conflict clause:
+ //
+ int i, j;
+ if (expensive_ccmin){
+ uint32_t abstract_level = 0;
+ for (i = 1; i < out_learnt.size(); i++)
+ abstract_level |= abstractLevel(var(out_learnt[i])); // (maintain an abstraction of levels involved in conflict)
+
+ out_learnt.copyTo(analyze_toclear);
+ for (i = j = 1; i < out_learnt.size(); i++)
+ if (reason[var(out_learnt[i])] == NULL || !litRedundant(out_learnt[i], abstract_level))
+ out_learnt[j++] = out_learnt[i];
+ }else{
+ out_learnt.copyTo(analyze_toclear);
+ for (i = j = 1; i < out_learnt.size(); i++){
+ Clause& c = *reason[var(out_learnt[i])];
+ for (int k = 1; k < c.size(); k++)
+ if (!seen[var(c[k])] && level[var(c[k])] > 0){
+ out_learnt[j++] = out_learnt[i];
+ break; }
+ }
+ }
+ max_literals += out_learnt.size();
+ out_learnt.shrink(i - j);
+ tot_literals += out_learnt.size();
+
+ // Find correct backtrack level:
+ //
+ if (out_learnt.size() == 1)
+ out_btlevel = 0;
+ else{
+ int max_i = 1;
+ for (int i = 2; i < out_learnt.size(); i++)
+ if (level[var(out_learnt[i])] > level[var(out_learnt[max_i])])
+ max_i = i;
+ Lit p = out_learnt[max_i];
+ out_learnt[max_i] = out_learnt[1];
+ out_learnt[1] = p;
+ out_btlevel = level[var(p)];
+ }
+
+
+ for (int j = 0; j < analyze_toclear.size(); j++) seen[var(analyze_toclear[j])] = 0; // ('seen[]' is now cleared)
+}
+
+
+// Check if 'p' can be removed. 'abstract_levels' is used to abort early if the algorithm is
+// visiting literals at levels that cannot be removed later.
+bool Solver::litRedundant(Lit p, uint32_t abstract_levels)
+{
+ analyze_stack.clear(); analyze_stack.push(p);
+ int top = analyze_toclear.size();
+ while (analyze_stack.size() > 0){
+ assert(reason[var(analyze_stack.last())] != NULL);
+ Clause& c = *reason[var(analyze_stack.last())]; analyze_stack.pop();
+
+ for (int i = 1; i < c.size(); i++){
+ Lit p = c[i];
+ if (!seen[var(p)] && level[var(p)] > 0){
+ if (reason[var(p)] != NULL && (abstractLevel(var(p)) & abstract_levels) != 0){
+ seen[var(p)] = 1;
+ analyze_stack.push(p);
+ analyze_toclear.push(p);
+ }else{
+ for (int j = top; j < analyze_toclear.size(); j++)
+ seen[var(analyze_toclear[j])] = 0;
+ analyze_toclear.shrink(analyze_toclear.size() - top);
+ return false;
+ }
+ }
+ }
+ }
+
+ return true;
+}
+
+
+/*_________________________________________________________________________________________________
+|
+| analyzeFinal : (p : Lit) -> [void]
+|
+| Description:
+| Specialized analysis procedure to express the final conflict in terms of assumptions.
+| Calculates the (possibly empty) set of assumptions that led to the assignment of 'p', and
+| stores the result in 'out_conflict'.
+|________________________________________________________________________________________________@*/
+void Solver::analyzeFinal(Lit p, vec<Lit>& out_conflict)
+{
+ out_conflict.clear();
+ out_conflict.push(p);
+
+ if (decisionLevel() == 0)
+ return;
+
+ seen[var(p)] = 1;
+
+ for (int i = trail.size()-1; i >= trail_lim[0]; i--){
+ Var x = var(trail[i]);
+ if (seen[x]){
+ if (reason[x] == NULL){
+ assert(level[x] > 0);
+ out_conflict.push(~trail[i]);
+ }else{
+ Clause& c = *reason[x];
+ for (int j = 1; j < c.size(); j++)
+ if (level[var(c[j])] > 0)
+ seen[var(c[j])] = 1;
+ }
+ seen[x] = 0;
+ }
+ }
+
+ seen[var(p)] = 0;
+}
+
+
+void Solver::uncheckedEnqueue(Lit p, Clause* from)
+{
+ assert(value(p) == l_Undef);
+ assigns [var(p)] = toInt(lbool(!sign(p))); // <<== abstract but not uttermost effecient
+ level [var(p)] = decisionLevel();
+ reason [var(p)] = from;
+ trail.push(p);
+}
+
+
+/*_________________________________________________________________________________________________
+|
+| propagate : [void] -> [Clause*]
+|
+| Description:
+| Propagates all enqueued facts. If a conflict arises, the conflicting clause is returned,
+| otherwise NULL.
+|
+| Post-conditions:
+| * the propagation queue is empty, even if there was a conflict.
+|________________________________________________________________________________________________@*/
+Clause* Solver::propagate()
+{
+ Clause* confl = NULL;
+ int num_props = 0;
+
+ while (qhead < trail.size()){
+ Lit p = trail[qhead++]; // 'p' is enqueued fact to propagate.
+ vec<Clause*>& ws = watches[toInt(p)];
+ Clause **i, **j, **end;
+ num_props++;
+
+ for (i = j = (Clause**)ws, end = i + ws.size(); i != end;){
+ Clause& c = **i++;
+
+ // Make sure the false literal is data[1]:
+ Lit false_lit = ~p;
+ if (c[0] == false_lit)
+ c[0] = c[1], c[1] = false_lit;
+
+ assert(c[1] == false_lit);
+
+ // If 0th watch is true, then clause is already satisfied.
+ Lit first = c[0];
+ if (value(first) == l_True){
+ *j++ = &c;
+ }else{
+ // Look for new watch:
+ for (int k = 2; k < c.size(); k++)
+ if (value(c[k]) != l_False){
+ c[1] = c[k]; c[k] = false_lit;
+ watches[toInt(~c[1])].push(&c);
+ goto FoundWatch; }
+
+ // Did not find watch -- clause is unit under assignment:
+ *j++ = &c;
+ if (value(first) == l_False){
+ confl = &c;
+ qhead = trail.size();
+ // Copy the remaining watches:
+ while (i < end)
+ *j++ = *i++;
+ }else
+ uncheckedEnqueue(first, &c);
+ }
+ FoundWatch:;
+ }
+ ws.shrink(i - j);
+ }
+ propagations += num_props;
+ simpDB_props -= num_props;
+
+ return confl;
+}
+
+/*_________________________________________________________________________________________________
+|
+| reduceDB : () -> [void]
+|
+| Description:
+| Remove half of the learnt clauses, minus the clauses locked by the current assignment. Locked
+| clauses are clauses that are reason to some assignment. Binary clauses are never removed.
+|________________________________________________________________________________________________@*/
+struct reduceDB_lt { bool operator () (Clause* x, Clause* y) { return x->size() > 2 && (y->size() == 2 || x->activity() < y->activity()); } };
+void Solver::reduceDB()
+{
+ int i, j;
+ double extra_lim = cla_inc / learnts.size(); // Remove any clause below this activity
+
+ sort(learnts, reduceDB_lt());
+ for (i = j = 0; i < learnts.size() / 2; i++){
+ if (learnts[i]->size() > 2 && !locked(*learnts[i]))
+ removeClause(*learnts[i]);
+ else
+ learnts[j++] = learnts[i];
+ }
+ for (; i < learnts.size(); i++){
+ if (learnts[i]->size() > 2 && !locked(*learnts[i]) && learnts[i]->activity() < extra_lim)
+ removeClause(*learnts[i]);
+ else
+ learnts[j++] = learnts[i];
+ }
+ learnts.shrink(i - j);
+}
+
+
+void Solver::removeSatisfied(vec<Clause*>& cs)
+{
+ int i,j;
+ for (i = j = 0; i < cs.size(); i++){
+ if (satisfied(*cs[i]))
+ removeClause(*cs[i]);
+ else
+ cs[j++] = cs[i];
+ }
+ cs.shrink(i - j);
+}
+
+
+/*_________________________________________________________________________________________________
+|
+| simplify : [void] -> [bool]
+|
+| Description:
+| Simplify the clause database according to the current top-level assigment. Currently, the only
+| thing done here is the removal of satisfied clauses, but more things can be put here.
+|________________________________________________________________________________________________@*/
+bool Solver::simplify()
+{
+ assert(decisionLevel() == 0);
+
+ if (!ok || propagate() != NULL)
+ return ok = false;
+
+ if (nAssigns() == simpDB_assigns || (simpDB_props > 0))
+ return true;
+
+ // Remove satisfied clauses:
+ removeSatisfied(learnts);
+ if (remove_satisfied) // Can be turned off.
+ removeSatisfied(clauses);
+
+ // Remove fixed variables from the variable heap:
+ order_heap.filter(VarFilter(*this));
+
+ simpDB_assigns = nAssigns();
+ simpDB_props = clauses_literals + learnts_literals; // (shouldn't depend on stats really, but it will do for now)
+
+ return true;
+}
+
+
+/*_________________________________________________________________________________________________
+|
+| search : (nof_conflicts : int) (nof_learnts : int) (params : const SearchParams&) -> [lbool]
+|
+| Description:
+| Search for a model the specified number of conflicts, keeping the number of learnt clauses
+| below the provided limit. NOTE! Use negative value for 'nof_conflicts' or 'nof_learnts' to
+| indicate infinity.
+|
+| Output:
+| 'l_True' if a partial assigment that is consistent with respect to the clauseset is found. If
+| all variables are decision variables, this means that the clause set is satisfiable. 'l_False'
+| if the clause set is unsatisfiable. 'l_Undef' if the bound on number of conflicts is reached.
+|________________________________________________________________________________________________@*/
+lbool Solver::search(int nof_conflicts, int nof_learnts)
+{
+ assert(ok);
+ int backtrack_level;
+ int conflictC = 0;
+ vec<Lit> learnt_clause;
+
+ starts++;
+
+ bool first = true;
+
+ for (;;){
+ Clause* confl = propagate();
+ if (confl != NULL){
+ // CONFLICT
+ conflicts++; conflictC++;
+ if (decisionLevel() == 0) return l_False;
+
+ first = false;
+
+ learnt_clause.clear();
+ analyze(confl, learnt_clause, backtrack_level);
+ cancelUntil(backtrack_level);
+ assert(value(learnt_clause[0]) == l_Undef);
+
+ if (learnt_clause.size() == 1){
+ uncheckedEnqueue(learnt_clause[0]);
+ }else{
+ Clause* c = Clause_new(learnt_clause, true);
+ learnts.push(c);
+ attachClause(*c);
+ claBumpActivity(*c);
+ uncheckedEnqueue(learnt_clause[0], c);
+ }
+
+ varDecayActivity();
+ claDecayActivity();
+
+ }else{
+ // NO CONFLICT
+
+ if (nof_conflicts >= 0 && conflictC >= nof_conflicts){
+ // Reached bound on number of conflicts:
+ progress_estimate = progressEstimate();
+ cancelUntil(0);
+ return l_Undef; }
+
+ // Simplify the set of problem clauses:
+ if (decisionLevel() == 0 && !simplify())
+ return l_False;
+
+ if (nof_learnts >= 0 && learnts.size()-nAssigns() >= nof_learnts)
+ // Reduce the set of learnt clauses:
+ reduceDB();
+
+ Lit next = lit_Undef;
+ while (decisionLevel() < assumptions.size()){
+ // Perform user provided assumption:
+ Lit p = assumptions[decisionLevel()];
+ if (value(p) == l_True){
+ // Dummy decision level:
+ newDecisionLevel();
+ }else if (value(p) == l_False){
+ analyzeFinal(~p, conflict);
+ return l_False;
+ }else{
+ next = p;
+ break;
+ }
+ }
+
+ if (next == lit_Undef){
+ // New variable decision:
+ decisions++;
+ next = pickBranchLit(polarity_mode, random_var_freq);
+
+ if (next == lit_Undef)
+ // Model found:
+ return l_True;
+ }
+
+ // Increase decision level and enqueue 'next'
+ assert(value(next) == l_Undef);
+ newDecisionLevel();
+ uncheckedEnqueue(next);
+ }
+ }
+}
+
+
+double Solver::progressEstimate() const
+{
+ double progress = 0;
+ double F = 1.0 / nVars();
+
+ for (int i = 0; i <= decisionLevel(); i++){
+ int beg = i == 0 ? 0 : trail_lim[i - 1];
+ int end = i == decisionLevel() ? trail.size() : trail_lim[i];
+ progress += pow(F, i) * (end - beg);
+ }
+
+ return progress / nVars();
+}
+
+
+bool Solver::solve(const vec<Lit>& assumps)
+{
+ model.clear();
+ conflict.clear();
+
+ if (!ok) return false;
+
+ assumps.copyTo(assumptions);
+
+ double nof_conflicts = restart_first;
+ double nof_learnts = nClauses() * learntsize_factor;
+ lbool status = l_Undef;
+
+ if (verbosity >= 1){
+ reportf("============================[ Search Statistics ]==============================\n");
+ reportf("| Conflicts | ORIGINAL | LEARNT | Progress |\n");
+ reportf("| | Vars Clauses Literals | Limit Clauses Lit/Cl | |\n");
+ reportf("===============================================================================\n");
+ }
+
+ // Search:
+ while (status == l_Undef){
+ if (verbosity >= 1)
+ reportf("| %9d | %7d %8d %8d | %8d %8d %6.0f | %6.3f %% |\n", (int)conflicts, order_heap.size(), nClauses(), (int)clauses_literals, (int)nof_learnts, nLearnts(), (double)learnts_literals/nLearnts(), progress_estimate*100), fflush(stdout);
+ status = search((int)nof_conflicts, (int)nof_learnts);
+ nof_conflicts *= restart_inc;
+ nof_learnts *= learntsize_inc;
+ }
+
+ if (verbosity >= 1)
+ reportf("===============================================================================\n");
+
+
+ if (status == l_True){
+ // Extend & copy model:
+ model.growTo(nVars());
+ for (int i = 0; i < nVars(); i++) model[i] = value(i);
+#ifndef NDEBUG
+ verifyModel();
+#endif
+ }else{
+ assert(status == l_False);
+ if (conflict.size() == 0)
+ ok = false;
+ }
+
+ cancelUntil(0);
+ return status == l_True;
+}
+
+//=================================================================================================
+// Debug methods:
+
+
+void Solver::verifyModel()
+{
+ bool failed = false;
+ for (int i = 0; i < clauses.size(); i++){
+ assert(clauses[i]->mark() == 0);
+ Clause& c = *clauses[i];
+ for (int j = 0; j < c.size(); j++)
+ if (modelValue(c[j]) == l_True)
+ goto next;
+
+ reportf("unsatisfied clause: ");
+ printClause(*clauses[i]);
+ reportf("\n");
+ failed = true;
+ next:;
+ }
+
+ assert(!failed);
+
+ reportf("Verified %d original clauses.\n", clauses.size());
+}
+
+
+void Solver::checkLiteralCount()
+{
+ // Check that sizes are calculated correctly:
+ int cnt = 0;
+ for (int i = 0; i < clauses.size(); i++)
+ if (clauses[i]->mark() == 0)
+ cnt += clauses[i]->size();
+
+ if ((int)clauses_literals != cnt){
+ fprintf(stderr, "literal count: %d, real value = %d\n", (int)clauses_literals, cnt);
+ assert((int)clauses_literals == cnt);
+ }
+}
--- /dev/null
+/****************************************************************************************[Solver.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Solver_h
+#define Solver_h
+
+#include <cstdio>
+
+#include "Vec.h"
+#include "Heap.h"
+#include "Alg.h"
+
+#include "SolverTypes.h"
+
+
+//=================================================================================================
+// Solver -- the main class:
+
+
+class Solver {
+public:
+
+ // Constructor/Destructor:
+ //
+ Solver();
+ ~Solver();
+
+ // Problem specification:
+ //
+ Var newVar (bool polarity = true, bool dvar = true); // Add a new variable with parameters specifying variable mode.
+ bool addClause (vec<Lit>& ps); // Add a clause to the solver. NOTE! 'ps' may be shrunk by this method!
+
+ // Solving:
+ //
+ bool simplify (); // Removes already satisfied clauses.
+ bool solve (const vec<Lit>& assumps); // Search for a model that respects a given set of assumptions.
+ bool solve (); // Search without assumptions.
+ bool okay () const; // FALSE means solver is in a conflicting state
+
+ // Variable mode:
+ //
+ void setPolarity (Var v, bool b); // Declare which polarity the decision heuristic should use for a variable. Requires mode 'polarity_user'.
+ void setDecisionVar (Var v, bool b); // Declare if a variable should be eligible for selection in the decision heuristic.
+
+ // Read state:
+ //
+ lbool value (Var x) const; // The current value of a variable.
+ lbool value (Lit p) const; // The current value of a literal.
+ lbool modelValue (Lit p) const; // The value of a literal in the last model. The last call to solve must have been satisfiable.
+ int nAssigns () const; // The current number of assigned literals.
+ int nClauses () const; // The current number of original clauses.
+ int nLearnts () const; // The current number of learnt clauses.
+ int nVars () const; // The current number of variables.
+
+ // Extra results: (read-only member variable)
+ //
+ vec<lbool> model; // If problem is satisfiable, this vector contains the model (if any).
+ vec<Lit> conflict; // If problem is unsatisfiable (possibly under assumptions),
+ // this vector represent the final conflict clause expressed in the assumptions.
+
+ // Mode of operation:
+ //
+ double var_decay; // Inverse of the variable activity decay factor. (default 1 / 0.95)
+ double clause_decay; // Inverse of the clause activity decay factor. (1 / 0.999)
+ double random_var_freq; // The frequency with which the decision heuristic tries to choose a random variable. (default 0.02)
+ int restart_first; // The initial restart limit. (default 100)
+ double restart_inc; // The factor with which the restart limit is multiplied in each restart. (default 1.5)
+ double learntsize_factor; // The intitial limit for learnt clauses is a factor of the original clauses. (default 1 / 3)
+ double learntsize_inc; // The limit for learnt clauses is multiplied with this factor each restart. (default 1.1)
+ bool expensive_ccmin; // Controls conflict clause minimization. (default TRUE)
+ int polarity_mode; // Controls which polarity the decision heuristic chooses. See enum below for allowed modes. (default polarity_false)
+ int verbosity; // Verbosity level. 0=silent, 1=some progress report (default 0)
+
+ enum { polarity_true = 0, polarity_false = 1, polarity_user = 2, polarity_rnd = 3 };
+
+ // Statistics: (read-only member variable)
+ //
+ uint64_t starts, decisions, rnd_decisions, propagations, conflicts;
+ uint64_t clauses_literals, learnts_literals, max_literals, tot_literals;
+
+protected:
+
+ // Helper structures:
+ //
+ struct VarOrderLt {
+ const vec<double>& activity;
+ bool operator () (Var x, Var y) const { return activity[x] > activity[y]; }
+ VarOrderLt(const vec<double>& act) : activity(act) { }
+ };
+
+ friend class VarFilter;
+ struct VarFilter {
+ const Solver& s;
+ VarFilter(const Solver& _s) : s(_s) {}
+ bool operator()(Var v) const { return toLbool(s.assigns[v]) == l_Undef && s.decision_var[v]; }
+ };
+
+ // Solver state:
+ //
+ bool ok; // If FALSE, the constraints are already unsatisfiable. No part of the solver state may be used!
+ vec<Clause*> clauses; // List of problem clauses.
+ vec<Clause*> learnts; // List of learnt clauses.
+ double cla_inc; // Amount to bump next clause with.
+ vec<double> activity; // A heuristic measurement of the activity of a variable.
+ double var_inc; // Amount to bump next variable with.
+ vec<vec<Clause*> > watches; // 'watches[lit]' is a list of constraints watching 'lit' (will go there if literal becomes true).
+ vec<char> assigns; // The current assignments (lbool:s stored as char:s).
+ vec<char> polarity; // The preferred polarity of each variable.
+ vec<char> decision_var; // Declares if a variable is eligible for selection in the decision heuristic.
+ vec<Lit> trail; // Assignment stack; stores all assigments made in the order they were made.
+ vec<int> trail_lim; // Separator indices for different decision levels in 'trail'.
+ vec<Clause*> reason; // 'reason[var]' is the clause that implied the variables current value, or 'NULL' if none.
+ vec<int> level; // 'level[var]' contains the level at which the assignment was made.
+ int qhead; // Head of queue (as index into the trail -- no more explicit propagation queue in MiniSat).
+ int simpDB_assigns; // Number of top-level assignments since last execution of 'simplify()'.
+ int64_t simpDB_props; // Remaining number of propagations that must be made before next execution of 'simplify()'.
+ vec<Lit> assumptions; // Current set of assumptions provided to solve by the user.
+ Heap<VarOrderLt> order_heap; // A priority queue of variables ordered with respect to the variable activity.
+ double random_seed; // Used by the random variable selection.
+ double progress_estimate;// Set by 'search()'.
+ bool remove_satisfied; // Indicates whether possibly inefficient linear scan for satisfied clauses should be performed in 'simplify'.
+
+ // Temporaries (to reduce allocation overhead). Each variable is prefixed by the method in which it is
+ // used, exept 'seen' wich is used in several places.
+ //
+ vec<char> seen;
+ vec<Lit> analyze_stack;
+ vec<Lit> analyze_toclear;
+ vec<Lit> add_tmp;
+
+ // Main internal methods:
+ //
+ void insertVarOrder (Var x); // Insert a variable in the decision order priority queue.
+ Lit pickBranchLit (int polarity_mode, double random_var_freq); // Return the next decision variable.
+ void newDecisionLevel (); // Begins a new decision level.
+ void uncheckedEnqueue (Lit p, Clause* from = NULL); // Enqueue a literal. Assumes value of literal is undefined.
+ bool enqueue (Lit p, Clause* from = NULL); // Test if fact 'p' contradicts current state, enqueue otherwise.
+ Clause* propagate (); // Perform unit propagation. Returns possibly conflicting clause.
+ void cancelUntil (int level); // Backtrack until a certain level.
+ void analyze (Clause* confl, vec<Lit>& out_learnt, int& out_btlevel); // (bt = backtrack)
+ void analyzeFinal (Lit p, vec<Lit>& out_conflict); // COULD THIS BE IMPLEMENTED BY THE ORDINARIY "analyze" BY SOME REASONABLE GENERALIZATION?
+ bool litRedundant (Lit p, uint32_t abstract_levels); // (helper method for 'analyze()')
+ lbool search (int nof_conflicts, int nof_learnts); // Search for a given number of conflicts.
+ void reduceDB (); // Reduce the set of learnt clauses.
+ void removeSatisfied (vec<Clause*>& cs); // Shrink 'cs' to contain only non-satisfied clauses.
+
+ // Maintaining Variable/Clause activity:
+ //
+ void varDecayActivity (); // Decay all variables with the specified factor. Implemented by increasing the 'bump' value instead.
+ void varBumpActivity (Var v); // Increase a variable with the current 'bump' value.
+ void claDecayActivity (); // Decay all clauses with the specified factor. Implemented by increasing the 'bump' value instead.
+ void claBumpActivity (Clause& c); // Increase a clause with the current 'bump' value.
+
+ // Operations on clauses:
+ //
+ void attachClause (Clause& c); // Attach a clause to watcher lists.
+ void detachClause (Clause& c); // Detach a clause to watcher lists.
+ void removeClause (Clause& c); // Detach and free a clause.
+ bool locked (const Clause& c) const; // Returns TRUE if a clause is a reason for some implication in the current state.
+ bool satisfied (const Clause& c) const; // Returns TRUE if a clause is satisfied in the current state.
+
+ // Misc:
+ //
+ int decisionLevel () const; // Gives the current decisionlevel.
+ uint32_t abstractLevel (Var x) const; // Used to represent an abstraction of sets of decision levels.
+ double progressEstimate () const; // DELETE THIS ?? IT'S NOT VERY USEFUL ...
+
+ // Debug:
+ void printLit (Lit l);
+ template<class C>
+ void printClause (const C& c);
+ void verifyModel ();
+ void checkLiteralCount();
+
+ // Static helpers:
+ //
+
+ // Returns a random float 0 <= x < 1. Seed must never be 0.
+ static inline double drand(double& seed) {
+ seed *= 1389796;
+ int q = (int)(seed / 2147483647);
+ seed -= (double)q * 2147483647;
+ return seed / 2147483647; }
+
+ // Returns a random integer 0 <= x < size. Seed must never be 0.
+ static inline int irand(double& seed, int size) {
+ return (int)(drand(seed) * size); }
+};
+
+
+//=================================================================================================
+// Implementation of inline methods:
+
+
+inline void Solver::insertVarOrder(Var x) {
+ if (!order_heap.inHeap(x) && decision_var[x]) order_heap.insert(x); }
+
+inline void Solver::varDecayActivity() { var_inc *= var_decay; }
+inline void Solver::varBumpActivity(Var v) {
+ if ( (activity[v] += var_inc) > 1e100 ) {
+ // Rescale:
+ for (int i = 0; i < nVars(); i++)
+ activity[i] *= 1e-100;
+ var_inc *= 1e-100; }
+
+ // Update order_heap with respect to new activity:
+ if (order_heap.inHeap(v))
+ order_heap.decrease(v); }
+
+inline void Solver::claDecayActivity() { cla_inc *= clause_decay; }
+inline void Solver::claBumpActivity (Clause& c) {
+ if ( (c.activity() += cla_inc) > 1e20 ) {
+ // Rescale:
+ for (int i = 0; i < learnts.size(); i++)
+ learnts[i]->activity() *= 1e-20;
+ cla_inc *= 1e-20; } }
+
+inline bool Solver::enqueue (Lit p, Clause* from) { return value(p) != l_Undef ? value(p) != l_False : (uncheckedEnqueue(p, from), true); }
+inline bool Solver::locked (const Clause& c) const { return reason[var(c[0])] == &c && value(c[0]) == l_True; }
+inline void Solver::newDecisionLevel() { trail_lim.push(trail.size()); }
+
+inline int Solver::decisionLevel () const { return trail_lim.size(); }
+inline uint32_t Solver::abstractLevel (Var x) const { return 1 << (level[x] & 31); }
+inline lbool Solver::value (Var x) const { return toLbool(assigns[x]); }
+inline lbool Solver::value (Lit p) const { return toLbool(assigns[var(p)]) ^ sign(p); }
+inline lbool Solver::modelValue (Lit p) const { return model[var(p)] ^ sign(p); }
+inline int Solver::nAssigns () const { return trail.size(); }
+inline int Solver::nClauses () const { return clauses.size(); }
+inline int Solver::nLearnts () const { return learnts.size(); }
+inline int Solver::nVars () const { return assigns.size(); }
+inline void Solver::setPolarity (Var v, bool b) { polarity [v] = (char)b; }
+inline void Solver::setDecisionVar(Var v, bool b) { decision_var[v] = (char)b; if (b) { insertVarOrder(v); } }
+inline bool Solver::solve () { vec<Lit> tmp; return solve(tmp); }
+inline bool Solver::okay () const { return ok; }
+
+
+
+//=================================================================================================
+// Debug + etc:
+
+
+#define reportf(format, args...) ( fflush(stdout), fprintf(stderr, format, ## args), fflush(stderr) )
+
+static inline void logLit(FILE* f, Lit l)
+{
+ fprintf(f, "%sx%d", sign(l) ? "~" : "", var(l)+1);
+}
+
+static inline void logLits(FILE* f, const vec<Lit>& ls)
+{
+ fprintf(f, "[ ");
+ if (ls.size() > 0){
+ logLit(f, ls[0]);
+ for (int i = 1; i < ls.size(); i++){
+ fprintf(f, ", ");
+ logLit(f, ls[i]);
+ }
+ }
+ fprintf(f, "] ");
+}
+
+static inline const char* showBool(bool b) { return b ? "true" : "false"; }
+
+
+// Just like 'assert()' but expression will be evaluated in the release version as well.
+static inline void check(bool expr) { assert(expr); }
+
+
+inline void Solver::printLit(Lit l)
+{
+ reportf("%s%d:%c", sign(l) ? "-" : "", var(l)+1, value(l) == l_True ? '1' : (value(l) == l_False ? '0' : 'X'));
+}
+
+
+template<class C>
+inline void Solver::printClause(const C& c)
+{
+ for (int i = 0; i < c.size(); i++){
+ printLit(c[i]);
+ fprintf(stderr, " ");
+ }
+}
+
+
+//=================================================================================================
+#endif
--- /dev/null
+/***********************************************************************************[SolverTypes.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+
+#ifndef SolverTypes_h
+#define SolverTypes_h
+
+#include <cassert>
+#include <stdint.h>
+
+//=================================================================================================
+// Variables, literals, lifted booleans, clauses:
+
+
+// NOTE! Variables are just integers. No abstraction here. They should be chosen from 0..N,
+// so that they can be used as array indices.
+
+typedef int Var;
+#define var_Undef (-1)
+
+
+class Lit {
+ int x;
+ public:
+ Lit() : x(2*var_Undef) { } // (lit_Undef)
+ explicit Lit(Var var, bool sign = false) : x((var+var) + (int)sign) { }
+
+ // Don't use these for constructing/deconstructing literals. Use the normal constructors instead.
+ friend int toInt (Lit p); // Guarantees small, positive integers suitable for array indexing.
+ friend Lit toLit (int i); // Inverse of 'toInt()'
+ friend Lit operator ~(Lit p);
+ friend bool sign (Lit p);
+ friend int var (Lit p);
+ friend Lit unsign (Lit p);
+ friend Lit id (Lit p, bool sgn);
+
+ bool operator == (Lit p) const { return x == p.x; }
+ bool operator != (Lit p) const { return x != p.x; }
+ bool operator < (Lit p) const { return x < p.x; } // '<' guarantees that p, ~p are adjacent in the ordering.
+};
+
+inline int toInt (Lit p) { return p.x; }
+inline Lit toLit (int i) { Lit p; p.x = i; return p; }
+inline Lit operator ~(Lit p) { Lit q; q.x = p.x ^ 1; return q; }
+inline bool sign (Lit p) { return p.x & 1; }
+inline int var (Lit p) { return p.x >> 1; }
+inline Lit unsign (Lit p) { Lit q; q.x = p.x & ~1; return q; }
+inline Lit id (Lit p, bool sgn) { Lit q; q.x = p.x ^ (int)sgn; return q; }
+
+const Lit lit_Undef(var_Undef, false); // }- Useful special constants.
+const Lit lit_Error(var_Undef, true ); // }
+
+
+//=================================================================================================
+// Lifted booleans:
+
+
+class lbool {
+ char value;
+ explicit lbool(int v) : value(v) { }
+
+public:
+ lbool() : value(0) { }
+ lbool(bool x) : value((int)x*2-1) { }
+ int toInt(void) const { return value; }
+
+ bool operator == (lbool b) const { return value == b.value; }
+ bool operator != (lbool b) const { return value != b.value; }
+ lbool operator ^ (bool b) const { return b ? lbool(-value) : lbool(value); }
+
+ friend int toInt (lbool l);
+ friend lbool toLbool(int v);
+};
+inline int toInt (lbool l) { return l.toInt(); }
+inline lbool toLbool(int v) { return lbool(v); }
+
+const lbool l_True = toLbool( 1);
+const lbool l_False = toLbool(-1);
+const lbool l_Undef = toLbool( 0);
+
+//=================================================================================================
+// Clause -- a simple class for representing a clause:
+
+
+class Clause {
+ uint32_t size_etc;
+ union { float act; uint32_t abst; } extra;
+ Lit data[0];
+
+public:
+ void calcAbstraction() {
+ uint32_t abstraction = 0;
+ for (int i = 0; i < size(); i++)
+ abstraction |= 1 << (var(data[i]) & 31);
+ extra.abst = abstraction; }
+
+ // NOTE: This constructor cannot be used directly (doesn't allocate enough memory).
+ template<class V>
+ Clause(const V& ps, bool learnt) {
+ size_etc = (ps.size() << 3) | (uint32_t)learnt;
+ for (int i = 0; i < ps.size(); i++) data[i] = ps[i];
+ if (learnt) extra.act = 0; else calcAbstraction(); }
+
+ // -- use this function instead:
+ template<class V>
+ friend Clause* Clause_new(const V& ps, bool learnt = false) {
+ assert(sizeof(Lit) == sizeof(uint32_t));
+ assert(sizeof(float) == sizeof(uint32_t));
+ void* mem = malloc(sizeof(Clause) + sizeof(uint32_t)*(ps.size()));
+ return new (mem) Clause(ps, learnt); }
+
+ int size () const { return size_etc >> 3; }
+ void shrink (int i) { assert(i <= size()); size_etc = (((size_etc >> 3) - i) << 3) | (size_etc & 7); }
+ void pop () { shrink(1); }
+ bool learnt () const { return size_etc & 1; }
+ uint32_t mark () const { return (size_etc >> 1) & 3; }
+ void mark (uint32_t m) { size_etc = (size_etc & ~6) | ((m & 3) << 1); }
+ const Lit& last () const { return data[size()-1]; }
+
+ // NOTE: somewhat unsafe to change the clause in-place! Must manually call 'calcAbstraction' afterwards for
+ // subsumption operations to behave correctly.
+ Lit& operator [] (int i) { return data[i]; }
+ Lit operator [] (int i) const { return data[i]; }
+ operator const Lit* (void) const { return data; }
+
+ float& activity () { return extra.act; }
+ uint32_t abstraction () const { return extra.abst; }
+
+ Lit subsumes (const Clause& other) const;
+ void strengthen (Lit p);
+};
+
+
+/*_________________________________________________________________________________________________
+|
+| subsumes : (other : const Clause&) -> Lit
+|
+| Description:
+| Checks if clause subsumes 'other', and at the same time, if it can be used to simplify 'other'
+| by subsumption resolution.
+|
+| Result:
+| lit_Error - No subsumption or simplification
+| lit_Undef - Clause subsumes 'other'
+| p - The literal p can be deleted from 'other'
+|________________________________________________________________________________________________@*/
+inline Lit Clause::subsumes(const Clause& other) const
+{
+ if (other.size() < size() || (extra.abst & ~other.extra.abst) != 0)
+ return lit_Error;
+
+ Lit ret = lit_Undef;
+ const Lit* c = (const Lit*)(*this);
+ const Lit* d = (const Lit*)other;
+
+ for (int i = 0; i < size(); i++) {
+ // search for c[i] or ~c[i]
+ for (int j = 0; j < other.size(); j++)
+ if (c[i] == d[j])
+ goto ok;
+ else if (ret == lit_Undef && c[i] == ~d[j]){
+ ret = c[i];
+ goto ok;
+ }
+
+ // did not find it
+ return lit_Error;
+ ok:;
+ }
+
+ return ret;
+}
+
+
+inline void Clause::strengthen(Lit p)
+{
+ remove(*this, p);
+ calcAbstraction();
+}
+
+#endif
--- /dev/null
+/*******************************************************************************************[Alg.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Alg_h
+#define Alg_h
+
+//=================================================================================================
+// Useful functions on vectors
+
+
+#if 1
+template<class V, class T>
+static inline void remove(V& ts, const T& t)
+{
+ int j = 0;
+ for (; j < ts.size() && ts[j] != t; j++);
+ assert(j < ts.size());
+ for (; j < ts.size()-1; j++) ts[j] = ts[j+1];
+ ts.pop();
+}
+#else
+template<class V, class T>
+static inline void remove(V& ts, const T& t)
+{
+ int j = 0;
+ for (; j < ts.size() && ts[j] != t; j++);
+ assert(j < ts.size());
+ ts[j] = ts.last();
+ ts.pop();
+}
+#endif
+
+template<class V, class T>
+static inline bool find(V& ts, const T& t)
+{
+ int j = 0;
+ for (; j < ts.size() && ts[j] != t; j++);
+ return j < ts.size();
+}
+
+#endif
--- /dev/null
+/******************************************************************************************[Heap.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef BasicHeap_h
+#define BasicHeap_h
+
+#include "Vec.h"
+
+//=================================================================================================
+// A heap implementation with support for decrease/increase key.
+
+
+template<class Comp>
+class BasicHeap {
+ Comp lt;
+ vec<int> heap; // heap of ints
+
+ // Index "traversal" functions
+ static inline int left (int i) { return i*2+1; }
+ static inline int right (int i) { return (i+1)*2; }
+ static inline int parent(int i) { return (i-1) >> 1; }
+
+ inline void percolateUp(int i)
+ {
+ int x = heap[i];
+ while (i != 0 && lt(x, heap[parent(i)])){
+ heap[i] = heap[parent(i)];
+ i = parent(i);
+ }
+ heap [i] = x;
+ }
+
+
+ inline void percolateDown(int i)
+ {
+ int x = heap[i];
+ while (left(i) < heap.size()){
+ int child = right(i) < heap.size() && lt(heap[right(i)], heap[left(i)]) ? right(i) : left(i);
+ if (!lt(heap[child], x)) break;
+ heap[i] = heap[child];
+ i = child;
+ }
+ heap[i] = x;
+ }
+
+
+ bool heapProperty(int i) {
+ return i >= heap.size()
+ || ((i == 0 || !lt(heap[i], heap[parent(i)])) && heapProperty(left(i)) && heapProperty(right(i))); }
+
+
+ public:
+ BasicHeap(const C& c) : comp(c) { }
+
+ int size () const { return heap.size(); }
+ bool empty () const { return heap.size() == 0; }
+ int operator[](int index) const { return heap[index+1]; }
+ void clear (bool dealloc = false) { heap.clear(dealloc); }
+ void insert (int n) { heap.push(n); percolateUp(heap.size()-1); }
+
+
+ int removeMin() {
+ int r = heap[0];
+ heap[0] = heap.last();
+ heap.pop();
+ if (heap.size() > 1) percolateDown(0);
+ return r;
+ }
+
+
+ // DEBUG: consistency checking
+ bool heapProperty() {
+ return heapProperty(1); }
+
+
+ // COMPAT: should be removed
+ int getmin () { return removeMin(); }
+};
+
+
+//=================================================================================================
+#endif
--- /dev/null
+/*******************************************************************************************[Vec.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef BoxedVec_h
+#define BoxedVec_h
+
+#include <cstdlib>
+#include <cassert>
+#include <new>
+
+//=================================================================================================
+// Automatically resizable arrays
+//
+// NOTE! Don't use this vector on datatypes that cannot be re-located in memory (with realloc)
+
+template<class T>
+class bvec {
+
+ static inline int imin(int x, int y) {
+ int mask = (x-y) >> (sizeof(int)*8-1);
+ return (x&mask) + (y&(~mask)); }
+
+ static inline int imax(int x, int y) {
+ int mask = (y-x) >> (sizeof(int)*8-1);
+ return (x&mask) + (y&(~mask)); }
+
+ struct Vec_t {
+ int sz;
+ int cap;
+ T data[0];
+
+ static Vec_t* alloc(Vec_t* x, int size){
+ x = (Vec_t*)realloc((void*)x, sizeof(Vec_t) + sizeof(T)*size);
+ x->cap = size;
+ return x;
+ }
+
+ };
+
+ Vec_t* ref;
+
+ static const int init_size = 2;
+ static int nextSize (int current) { return (current * 3 + 1) >> 1; }
+ static int fitSize (int needed) { int x; for (x = init_size; needed > x; x = nextSize(x)); return x; }
+
+ void fill (int size) {
+ assert(ref != NULL);
+ for (T* i = ref->data; i < ref->data + size; i++)
+ new (i) T();
+ }
+
+ void fill (int size, const T& pad) {
+ assert(ref != NULL);
+ for (T* i = ref->data; i < ref->data + size; i++)
+ new (i) T(pad);
+ }
+
+ // Don't allow copying (error prone):
+ altvec<T>& operator = (altvec<T>& other) { assert(0); }
+ altvec (altvec<T>& other) { assert(0); }
+
+public:
+ void clear (bool dealloc = false) {
+ if (ref != NULL){
+ for (int i = 0; i < ref->sz; i++)
+ (*ref).data[i].~T();
+
+ if (dealloc) {
+ free(ref); ref = NULL;
+ }else
+ ref->sz = 0;
+ }
+ }
+
+ // Constructors:
+ altvec(void) : ref (NULL) { }
+ altvec(int size) : ref (Vec_t::alloc(NULL, fitSize(size))) { fill(size); ref->sz = size; }
+ altvec(int size, const T& pad) : ref (Vec_t::alloc(NULL, fitSize(size))) { fill(size, pad); ref->sz = size; }
+ ~altvec(void) { clear(true); }
+
+ // Ownership of underlying array:
+ operator T* (void) { return ref->data; } // (unsafe but convenient)
+ operator const T* (void) const { return ref->data; }
+
+ // Size operations:
+ int size (void) const { return ref != NULL ? ref->sz : 0; }
+
+ void pop (void) { assert(ref != NULL && ref->sz > 0); int last = --ref->sz; ref->data[last].~T(); }
+ void push (const T& elem) {
+ int size = ref != NULL ? ref->sz : 0;
+ int cap = ref != NULL ? ref->cap : 0;
+ if (size == cap){
+ cap = cap != 0 ? nextSize(cap) : init_size;
+ ref = Vec_t::alloc(ref, cap);
+ }
+ //new (&ref->data[size]) T(elem);
+ ref->data[size] = elem;
+ ref->sz = size+1;
+ }
+
+ void push () {
+ int size = ref != NULL ? ref->sz : 0;
+ int cap = ref != NULL ? ref->cap : 0;
+ if (size == cap){
+ cap = cap != 0 ? nextSize(cap) : init_size;
+ ref = Vec_t::alloc(ref, cap);
+ }
+ new (&ref->data[size]) T();
+ ref->sz = size+1;
+ }
+
+ void shrink (int nelems) { for (int i = 0; i < nelems; i++) pop(); }
+ void shrink_(int nelems) { for (int i = 0; i < nelems; i++) pop(); }
+ void growTo (int size) { while (this->size() < size) push(); }
+ void growTo (int size, const T& pad) { while (this->size() < size) push(pad); }
+ void capacity (int size) { growTo(size); }
+
+ const T& last (void) const { return ref->data[ref->sz-1]; }
+ T& last (void) { return ref->data[ref->sz-1]; }
+
+ // Vector interface:
+ const T& operator [] (int index) const { return ref->data[index]; }
+ T& operator [] (int index) { return ref->data[index]; }
+
+ void copyTo(altvec<T>& copy) const { copy.clear(); for (int i = 0; i < size(); i++) copy.push(ref->data[i]); }
+ void moveTo(altvec<T>& dest) { dest.clear(true); dest.ref = ref; ref = NULL; }
+
+};
+
+
+#endif
--- /dev/null
+/******************************************************************************************[Heap.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Heap_h
+#define Heap_h
+
+#include "Vec.h"
+
+//=================================================================================================
+// A heap implementation with support for decrease/increase key.
+
+
+template<class Comp>
+class Heap {
+ Comp lt;
+ vec<int> heap; // heap of ints
+ vec<int> indices; // int -> index in heap
+
+ // Index "traversal" functions
+ static inline int left (int i) { return i*2+1; }
+ static inline int right (int i) { return (i+1)*2; }
+ static inline int parent(int i) { return (i-1) >> 1; }
+
+
+ inline void percolateUp(int i)
+ {
+ int x = heap[i];
+ while (i != 0 && lt(x, heap[parent(i)])){
+ heap[i] = heap[parent(i)];
+ indices[heap[i]] = i;
+ i = parent(i);
+ }
+ heap [i] = x;
+ indices[x] = i;
+ }
+
+
+ inline void percolateDown(int i)
+ {
+ int x = heap[i];
+ while (left(i) < heap.size()){
+ int child = right(i) < heap.size() && lt(heap[right(i)], heap[left(i)]) ? right(i) : left(i);
+ if (!lt(heap[child], x)) break;
+ heap[i] = heap[child];
+ indices[heap[i]] = i;
+ i = child;
+ }
+ heap [i] = x;
+ indices[x] = i;
+ }
+
+
+ bool heapProperty (int i) const {
+ return i >= heap.size()
+ || ((i == 0 || !lt(heap[i], heap[parent(i)])) && heapProperty(left(i)) && heapProperty(right(i))); }
+
+
+ public:
+ Heap(const Comp& c) : lt(c) { }
+
+ int size () const { return heap.size(); }
+ bool empty () const { return heap.size() == 0; }
+ bool inHeap (int n) const { return n < indices.size() && indices[n] >= 0; }
+ int operator[](int index) const { assert(index < heap.size()); return heap[index]; }
+
+ void decrease (int n) { assert(inHeap(n)); percolateUp(indices[n]); }
+
+ // RENAME WHEN THE DEPRECATED INCREASE IS REMOVED.
+ void increase_ (int n) { assert(inHeap(n)); percolateDown(indices[n]); }
+
+
+ void insert(int n)
+ {
+ indices.growTo(n+1, -1);
+ assert(!inHeap(n));
+
+ indices[n] = heap.size();
+ heap.push(n);
+ percolateUp(indices[n]);
+ }
+
+
+ int removeMin()
+ {
+ int x = heap[0];
+ heap[0] = heap.last();
+ indices[heap[0]] = 0;
+ indices[x] = -1;
+ heap.pop();
+ if (heap.size() > 1) percolateDown(0);
+ return x;
+ }
+
+
+ void clear(bool dealloc = false)
+ {
+ for (int i = 0; i < heap.size(); i++)
+ indices[heap[i]] = -1;
+#ifdef NDEBUG
+ for (int i = 0; i < indices.size(); i++)
+ assert(indices[i] == -1);
+#endif
+ heap.clear(dealloc);
+ }
+
+
+ // Fool proof variant of insert/decrease/increase
+ void update (int n)
+ {
+ if (!inHeap(n))
+ insert(n);
+ else {
+ percolateUp(indices[n]);
+ percolateDown(indices[n]);
+ }
+ }
+
+
+ // Delete elements from the heap using a given filter function (-object).
+ // *** this could probaly be replaced with a more general "buildHeap(vec<int>&)" method ***
+ template <class F>
+ void filter(const F& filt) {
+ int i,j;
+ for (i = j = 0; i < heap.size(); i++)
+ if (filt(heap[i])){
+ heap[j] = heap[i];
+ indices[heap[i]] = j++;
+ }else
+ indices[heap[i]] = -1;
+
+ heap.shrink(i - j);
+ for (int i = heap.size() / 2 - 1; i >= 0; i--)
+ percolateDown(i);
+
+ assert(heapProperty());
+ }
+
+
+ // DEBUG: consistency checking
+ bool heapProperty() const {
+ return heapProperty(1); }
+
+
+ // COMPAT: should be removed
+ void setBounds (int n) { }
+ void increase (int n) { decrease(n); }
+ int getmin () { return removeMin(); }
+
+};
+
+
+//=================================================================================================
+#endif
--- /dev/null
+/*******************************************************************************************[Map.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Map_h
+#define Map_h
+
+#include <stdint.h>
+
+#include "Vec.h"
+
+//=================================================================================================
+// Default hash/equals functions
+//
+
+template<class K> struct Hash { uint32_t operator()(const K& k) const { return hash(k); } };
+template<class K> struct Equal { bool operator()(const K& k1, const K& k2) const { return k1 == k2; } };
+
+template<class K> struct DeepHash { uint32_t operator()(const K* k) const { return hash(*k); } };
+template<class K> struct DeepEqual { bool operator()(const K* k1, const K* k2) const { return *k1 == *k2; } };
+
+//=================================================================================================
+// Some primes
+//
+
+static const int nprimes = 25;
+static const int primes [nprimes] = { 31, 73, 151, 313, 643, 1291, 2593, 5233, 10501, 21013, 42073, 84181, 168451, 337219, 674701, 1349473, 2699299, 5398891, 10798093, 21596719, 43193641, 86387383, 172775299, 345550609, 691101253 };
+
+//=================================================================================================
+// Hash table implementation of Maps
+//
+
+template<class K, class D, class H = Hash<K>, class E = Equal<K> >
+class Map {
+ struct Pair { K key; D data; };
+
+ H hash;
+ E equals;
+
+ vec<Pair>* table;
+ int cap;
+ int size;
+
+ // Don't allow copying (error prone):
+ Map<K,D,H,E>& operator = (Map<K,D,H,E>& other) { assert(0); }
+ Map (Map<K,D,H,E>& other) { assert(0); }
+
+ int32_t index (const K& k) const { return hash(k) % cap; }
+ void _insert (const K& k, const D& d) { table[index(k)].push(); table[index(k)].last().key = k; table[index(k)].last().data = d; }
+ void rehash () {
+ const vec<Pair>* old = table;
+
+ int newsize = primes[0];
+ for (int i = 1; newsize <= cap && i < nprimes; i++)
+ newsize = primes[i];
+
+ table = new vec<Pair>[newsize];
+
+ for (int i = 0; i < cap; i++){
+ for (int j = 0; j < old[i].size(); j++){
+ _insert(old[i][j].key, old[i][j].data); }}
+
+ delete [] old;
+
+ cap = newsize;
+ }
+
+
+ public:
+
+ Map () : table(NULL), cap(0), size(0) {}
+ Map (const H& h, const E& e) : Map(), hash(h), equals(e) {}
+ ~Map () { delete [] table; }
+
+ void insert (const K& k, const D& d) { if (size+1 > cap / 2) rehash(); _insert(k, d); size++; }
+ bool peek (const K& k, D& d) {
+ if (size == 0) return false;
+ const vec<Pair>& ps = table[index(k)];
+ for (int i = 0; i < ps.size(); i++)
+ if (equals(ps[i].key, k)){
+ d = ps[i].data;
+ return true; }
+ return false;
+ }
+
+ void remove (const K& k) {
+ assert(table != NULL);
+ vec<Pair>& ps = table[index(k)];
+ int j = 0;
+ for (; j < ps.size() && !equals(ps[j].key, k); j++);
+ assert(j < ps.size());
+ ps[j] = ps.last();
+ ps.pop();
+ }
+
+ void clear () {
+ cap = size = 0;
+ delete [] table;
+ table = NULL;
+ }
+};
+
+#endif
--- /dev/null
+/*****************************************************************************************[Queue.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Queue_h
+#define Queue_h
+
+#include "Vec.h"
+
+//=================================================================================================
+
+
+template <class T>
+class Queue {
+ vec<T> elems;
+ int first;
+
+public:
+ Queue(void) : first(0) { }
+
+ void insert(T x) { elems.push(x); }
+ T peek () const { return elems[first]; }
+ void pop () { first++; }
+
+ void clear(bool dealloc = false) { elems.clear(dealloc); first = 0; }
+ int size(void) { return elems.size() - first; }
+
+ //bool has(T x) { for (int i = first; i < elems.size(); i++) if (elems[i] == x) return true; return false; }
+
+ const T& operator [] (int index) const { return elems[first + index]; }
+
+};
+
+//template<class T>
+//class Queue {
+// vec<T> buf;
+// int first;
+// int end;
+//
+//public:
+// typedef T Key;
+//
+// Queue() : buf(1), first(0), end(0) {}
+//
+// void clear () { buf.shrinkTo(1); first = end = 0; }
+// int size () { return (end >= first) ? end - first : end - first + buf.size(); }
+//
+// T peek () { assert(first != end); return buf[first]; }
+// void pop () { assert(first != end); first++; if (first == buf.size()) first = 0; }
+// void insert(T elem) { // INVARIANT: buf[end] is always unused
+// buf[end++] = elem;
+// if (end == buf.size()) end = 0;
+// if (first == end){ // Resize:
+// vec<T> tmp((buf.size()*3 + 1) >> 1);
+// //**/printf("queue alloc: %d elems (%.1f MB)\n", tmp.size(), tmp.size() * sizeof(T) / 1000000.0);
+// int i = 0;
+// for (int j = first; j < buf.size(); j++) tmp[i++] = buf[j];
+// for (int j = 0 ; j < end ; j++) tmp[i++] = buf[j];
+// first = 0;
+// end = buf.size();
+// tmp.moveTo(buf);
+// }
+// }
+//};
+
+//=================================================================================================
+#endif
--- /dev/null
+/******************************************************************************************[Sort.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Sort_h
+#define Sort_h
+
+#include "Vec.h"
+
+//=================================================================================================
+// Some sorting algorithms for vec's
+
+
+template<class T>
+struct LessThan_default {
+ bool operator () (T x, T y) { return x < y; }
+};
+
+
+template <class T, class LessThan>
+void selectionSort(T* array, int size, LessThan lt)
+{
+ int i, j, best_i;
+ T tmp;
+
+ for (i = 0; i < size-1; i++){
+ best_i = i;
+ for (j = i+1; j < size; j++){
+ if (lt(array[j], array[best_i]))
+ best_i = j;
+ }
+ tmp = array[i]; array[i] = array[best_i]; array[best_i] = tmp;
+ }
+}
+template <class T> static inline void selectionSort(T* array, int size) {
+ selectionSort(array, size, LessThan_default<T>()); }
+
+template <class T, class LessThan>
+void sort(T* array, int size, LessThan lt)
+{
+ if (size <= 15)
+ selectionSort(array, size, lt);
+
+ else{
+ T pivot = array[size / 2];
+ T tmp;
+ int i = -1;
+ int j = size;
+
+ for(;;){
+ do i++; while(lt(array[i], pivot));
+ do j--; while(lt(pivot, array[j]));
+
+ if (i >= j) break;
+
+ tmp = array[i]; array[i] = array[j]; array[j] = tmp;
+ }
+
+ sort(array , i , lt);
+ sort(&array[i], size-i, lt);
+ }
+}
+template <class T> static inline void sort(T* array, int size) {
+ sort(array, size, LessThan_default<T>()); }
+
+
+//=================================================================================================
+// For 'vec's:
+
+
+template <class T, class LessThan> void sort(vec<T>& v, LessThan lt) {
+ sort((T*)v, v.size(), lt); }
+template <class T> void sort(vec<T>& v) {
+ sort(v, LessThan_default<T>()); }
+
+
+//=================================================================================================
+#endif
--- /dev/null
+/*******************************************************************************************[Vec.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Vec_h
+#define Vec_h
+
+#include <cstdlib>
+#include <cassert>
+#include <new>
+
+//=================================================================================================
+// Automatically resizable arrays
+//
+// NOTE! Don't use this vector on datatypes that cannot be re-located in memory (with realloc)
+
+template<class T>
+class vec {
+ T* data;
+ int sz;
+ int cap;
+
+ void init(int size, const T& pad);
+ void grow(int min_cap);
+
+ // Don't allow copying (error prone):
+ vec<T>& operator = (vec<T>& other) { assert(0); return *this; }
+ vec (vec<T>& other) { assert(0); }
+
+ static inline int imin(int x, int y) {
+ int mask = (x-y) >> (sizeof(int)*8-1);
+ return (x&mask) + (y&(~mask)); }
+
+ static inline int imax(int x, int y) {
+ int mask = (y-x) >> (sizeof(int)*8-1);
+ return (x&mask) + (y&(~mask)); }
+
+public:
+ // Types:
+ typedef int Key;
+ typedef T Datum;
+
+ // Constructors:
+ vec(void) : data(NULL) , sz(0) , cap(0) { }
+ vec(int size) : data(NULL) , sz(0) , cap(0) { growTo(size); }
+ vec(int size, const T& pad) : data(NULL) , sz(0) , cap(0) { growTo(size, pad); }
+ vec(T* array, int size) : data(array), sz(size), cap(size) { } // (takes ownership of array -- will be deallocated with 'free()')
+ ~vec(void) { clear(true); }
+
+ // Ownership of underlying array:
+ T* release (void) { T* ret = data; data = NULL; sz = 0; cap = 0; return ret; }
+ operator T* (void) { return data; } // (unsafe but convenient)
+ operator const T* (void) const { return data; }
+
+ // Size operations:
+ int size (void) const { return sz; }
+ void shrink (int nelems) { assert(nelems <= sz); for (int i = 0; i < nelems; i++) sz--, data[sz].~T(); }
+ void shrink_(int nelems) { assert(nelems <= sz); sz -= nelems; }
+ void pop (void) { sz--, data[sz].~T(); }
+ void growTo (int size);
+ void growTo (int size, const T& pad);
+ void clear (bool dealloc = false);
+ void capacity (int size) { grow(size); }
+
+ // Stack interface:
+#if 1
+ void push (void) { if (sz == cap) { cap = imax(2, (cap*3+1)>>1); data = (T*)realloc(data, cap * sizeof(T)); } new (&data[sz]) T(); sz++; }
+ //void push (const T& elem) { if (sz == cap) { cap = imax(2, (cap*3+1)>>1); data = (T*)realloc(data, cap * sizeof(T)); } new (&data[sz]) T(elem); sz++; }
+ void push (const T& elem) { if (sz == cap) { cap = imax(2, (cap*3+1)>>1); data = (T*)realloc(data, cap * sizeof(T)); } data[sz++] = elem; }
+ void push_ (const T& elem) { assert(sz < cap); data[sz++] = elem; }
+#else
+ void push (void) { if (sz == cap) grow(sz+1); new (&data[sz]) T() ; sz++; }
+ void push (const T& elem) { if (sz == cap) grow(sz+1); new (&data[sz]) T(elem); sz++; }
+#endif
+
+ const T& last (void) const { return data[sz-1]; }
+ T& last (void) { return data[sz-1]; }
+
+ // Vector interface:
+ const T& operator [] (int index) const { return data[index]; }
+ T& operator [] (int index) { return data[index]; }
+
+
+ // Duplicatation (preferred instead):
+ void copyTo(vec<T>& copy) const { copy.clear(); copy.growTo(sz); for (int i = 0; i < sz; i++) new (©[i]) T(data[i]); }
+ void moveTo(vec<T>& dest) { dest.clear(true); dest.data = data; dest.sz = sz; dest.cap = cap; data = NULL; sz = 0; cap = 0; }
+};
+
+template<class T>
+void vec<T>::grow(int min_cap) {
+ if (min_cap <= cap) return;
+ if (cap == 0) cap = (min_cap >= 2) ? min_cap : 2;
+ else do cap = (cap*3+1) >> 1; while (cap < min_cap);
+ data = (T*)realloc(data, cap * sizeof(T)); }
+
+template<class T>
+void vec<T>::growTo(int size, const T& pad) {
+ if (sz >= size) return;
+ grow(size);
+ for (int i = sz; i < size; i++) new (&data[i]) T(pad);
+ sz = size; }
+
+template<class T>
+void vec<T>::growTo(int size) {
+ if (sz >= size) return;
+ grow(size);
+ for (int i = sz; i < size; i++) new (&data[i]) T();
+ sz = size; }
+
+template<class T>
+void vec<T>::clear(bool dealloc) {
+ if (data != NULL){
+ for (int i = 0; i < sz; i++) data[i].~T();
+ sz = 0;
+ if (dealloc) free(data), data = NULL, cap = 0; } }
+
+
+#endif
--- /dev/null
+##
+## Template makefile for Standard, Profile, Debug, Release, and Release-static versions
+##
+## eg: "make rs" for a statically linked release version.
+## "make d" for a debug version (no optimizations).
+## "make" for the standard version (optimized, but with debug information and assertions active)
+
+CSRCS ?= $(wildcard *.C)
+CHDRS ?= $(wildcard *.h)
+COBJS ?= $(addsuffix .o, $(basename $(CSRCS)))
+
+PCOBJS = $(addsuffix p, $(COBJS))
+DCOBJS = $(addsuffix d, $(COBJS))
+RCOBJS = $(addsuffix r, $(COBJS))
+
+EXEC ?= $(notdir $(shell pwd))
+LIB ?= $(EXEC)
+
+CXX ?= g++
+CFLAGS ?= -Wall
+LFLAGS ?= -Wall
+
+COPTIMIZE ?= -O3
+
+.PHONY : s p d r rs lib libd clean
+
+s: $(EXEC)
+p: $(EXEC)_profile
+d: $(EXEC)_debug
+r: $(EXEC)_release
+rs: $(EXEC)_static
+lib: lib$(LIB).a
+libd: lib$(LIB)d.a
+
+## Compile options
+%.o: CFLAGS +=$(COPTIMIZE) -ggdb -D DEBUG
+%.op: CFLAGS +=$(COPTIMIZE) -pg -ggdb -D NDEBUG
+%.od: CFLAGS +=-O0 -ggdb -D DEBUG # -D INVARIANTS
+%.or: CFLAGS +=$(COPTIMIZE) -D NDEBUG
+
+## Link options
+$(EXEC): LFLAGS := -ggdb $(LFLAGS)
+$(EXEC)_profile: LFLAGS := -ggdb -pg $(LFLAGS)
+$(EXEC)_debug: LFLAGS := -ggdb $(LFLAGS)
+$(EXEC)_release: LFLAGS := $(LFLAGS)
+$(EXEC)_static: LFLAGS := --static $(LFLAGS)
+
+## Dependencies
+$(EXEC): $(COBJS)
+$(EXEC)_profile: $(PCOBJS)
+$(EXEC)_debug: $(DCOBJS)
+$(EXEC)_release: $(RCOBJS)
+$(EXEC)_static: $(RCOBJS)
+
+lib$(LIB).a: $(filter-out Main.or, $(RCOBJS))
+lib$(LIB)d.a: $(filter-out Main.od, $(DCOBJS))
+
+
+## Build rule
+%.o %.op %.od %.or: %.C
+ @echo Compiling: "$@ ( $< )"
+ @$(CXX) $(CFLAGS) -c -o $@ $<
+
+## Linking rules (standard/profile/debug/release)
+$(EXEC) $(EXEC)_profile $(EXEC)_debug $(EXEC)_release $(EXEC)_static:
+ @echo Linking: "$@ ( $^ )"
+ @$(CXX) $^ $(LFLAGS) -o $@
+
+## Library rule
+lib$(LIB).a lib$(LIB)d.a:
+ @echo Library: "$@ ( $^ )"
+ @rm -f $@
+ @ar cq $@ $^
+
+## Clean rule
+clean:
+ @rm -f $(EXEC) $(EXEC)_profile $(EXEC)_debug $(EXEC)_release $(EXEC)_static \
+ $(COBJS) $(PCOBJS) $(DCOBJS) $(RCOBJS) *.core depend.mak lib$(LIB).a lib$(LIB)d.a
+
+## Make dependencies
+depend.mk: $(CSRCS) $(CHDRS)
+ @echo Making dependencies ...
+ @$(CXX) $(CFLAGS) -MM $(CSRCS) > depend.mk
+ @cp depend.mk /tmp/depend.mk.tmp
+ @sed "s/o:/op:/" /tmp/depend.mk.tmp >> depend.mk
+ @sed "s/o:/od:/" /tmp/depend.mk.tmp >> depend.mk
+ @sed "s/o:/or:/" /tmp/depend.mk.tmp >> depend.mk
+ @rm /tmp/depend.mk.tmp
+
+-include depend.mk
--- /dev/null
+/******************************************************************************************[Main.C]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include <ctime>
+#include <cstring>
+#include <stdint.h>
+#include <errno.h>
+
+#include <signal.h>
+#include <zlib.h>
+
+#include "SimpSolver.h"
+
+/*************************************************************************************/
+#ifdef _MSC_VER
+#include <ctime>
+
+static inline double cpuTime(void) {
+ return (double)clock() / CLOCKS_PER_SEC; }
+#else
+
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <unistd.h>
+
+static inline double cpuTime(void) {
+ struct rusage ru;
+ getrusage(RUSAGE_SELF, &ru);
+ return (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000; }
+#endif
+
+
+#if defined(__linux__)
+static inline int memReadStat(int field)
+{
+ char name[256];
+ pid_t pid = getpid();
+ sprintf(name, "/proc/%d/statm", pid);
+ FILE* in = fopen(name, "rb");
+ if (in == NULL) return 0;
+ int value;
+ for (; field >= 0; field--)
+ fscanf(in, "%d", &value);
+ fclose(in);
+ return value;
+}
+static inline uint64_t memUsed() { return (uint64_t)memReadStat(0) * (uint64_t)getpagesize(); }
+
+
+#elif defined(__FreeBSD__)
+static inline uint64_t memUsed(void) {
+ struct rusage ru;
+ getrusage(RUSAGE_SELF, &ru);
+ return ru.ru_maxrss*1024; }
+
+
+#else
+static inline uint64_t memUsed() { return 0; }
+#endif
+
+#if defined(__linux__)
+#include <fpu_control.h>
+#endif
+
+
+//=================================================================================================
+// DIMACS Parser:
+
+#define CHUNK_LIMIT 1048576
+
+class StreamBuffer {
+ gzFile in;
+ char buf[CHUNK_LIMIT];
+ int pos;
+ int size;
+
+ void assureLookahead() {
+ if (pos >= size) {
+ pos = 0;
+ size = gzread(in, buf, sizeof(buf)); } }
+
+public:
+ StreamBuffer(gzFile i) : in(i), pos(0), size(0) {
+ assureLookahead(); }
+
+ int operator * () { return (pos >= size) ? EOF : buf[pos]; }
+ void operator ++ () { pos++; assureLookahead(); }
+};
+
+//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+template<class B>
+static void skipWhitespace(B& in) {
+ while ((*in >= 9 && *in <= 13) || *in == 32)
+ ++in; }
+
+template<class B>
+static void skipLine(B& in) {
+ for (;;){
+ if (*in == EOF || *in == '\0') return;
+ if (*in == '\n') { ++in; return; }
+ ++in; } }
+
+template<class B>
+static int parseInt(B& in) {
+ int val = 0;
+ bool neg = false;
+ skipWhitespace(in);
+ if (*in == '-') neg = true, ++in;
+ else if (*in == '+') ++in;
+ if (*in < '0' || *in > '9') reportf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+ while (*in >= '0' && *in <= '9')
+ val = val*10 + (*in - '0'),
+ ++in;
+ return neg ? -val : val; }
+
+template<class B>
+static void readClause(B& in, SimpSolver& S, vec<Lit>& lits) {
+ int parsed_lit, var;
+ lits.clear();
+ for (;;){
+ parsed_lit = parseInt(in);
+ if (parsed_lit == 0) break;
+ var = abs(parsed_lit)-1;
+ while (var >= S.nVars()) S.newVar();
+ lits.push( (parsed_lit > 0) ? Lit(var) : ~Lit(var) );
+ }
+}
+
+template<class B>
+static bool match(B& in, char* str) {
+ for (; *str != 0; ++str, ++in)
+ if (*str != *in)
+ return false;
+ return true;
+}
+
+
+template<class B>
+static void parse_DIMACS_main(B& in, SimpSolver& S) {
+ vec<Lit> lits;
+ for (;;){
+ skipWhitespace(in);
+ if (*in == EOF) break;
+ else if (*in == 'p'){
+ if (match(in, "p cnf")){
+ int vars = parseInt(in);
+ int clauses = parseInt(in);
+ reportf("| Number of variables: %-12d |\n", vars);
+ reportf("| Number of clauses: %-12d |\n", clauses);
+
+ // SATRACE'06 hack
+ if (clauses > 4000000)
+ S.eliminate(true);
+ }else{
+ reportf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+ }
+ } else if (*in == 'c' || *in == 'p')
+ skipLine(in);
+ else{
+ readClause(in, S, lits);
+ S.addClause(lits); }
+ }
+}
+
+// Inserts problem into solver.
+//
+static void parse_DIMACS(gzFile input_stream, SimpSolver& S) {
+ StreamBuffer in(input_stream);
+ parse_DIMACS_main(in, S); }
+
+
+//=================================================================================================
+
+
+void printStats(Solver& S)
+{
+ double cpu_time = cpuTime();
+ uint64_t mem_used = memUsed();
+ reportf("restarts : %lld\n", S.starts);
+ reportf("conflicts : %-12lld (%.0f /sec)\n", S.conflicts , S.conflicts /cpu_time);
+ reportf("decisions : %-12lld (%4.2f %% random) (%.0f /sec)\n", S.decisions, (float)S.rnd_decisions*100 / (float)S.decisions, S.decisions /cpu_time);
+ reportf("propagations : %-12lld (%.0f /sec)\n", S.propagations, S.propagations/cpu_time);
+ reportf("conflict literals : %-12lld (%4.2f %% deleted)\n", S.tot_literals, (S.max_literals - S.tot_literals)*100 / (double)S.max_literals);
+ if (mem_used != 0) reportf("Memory used : %.2f MB\n", mem_used / 1048576.0);
+ reportf("CPU time : %g s\n", cpu_time);
+}
+
+SimpSolver* solver;
+static void SIGINT_handler(int signum) {
+ reportf("\n"); reportf("*** INTERRUPTED ***\n");
+ printStats(*solver);
+ reportf("\n"); reportf("*** INTERRUPTED ***\n");
+ exit(1); }
+
+
+//=================================================================================================
+// Main:
+
+void printUsage(char** argv)
+{
+ reportf("USAGE: %s [options] <input-file> <result-output-file>\n\n where input may be either in plain or gzipped DIMACS.\n\n", argv[0]);
+ reportf("OPTIONS:\n\n");
+ reportf(" -pre = {none,once}\n");
+ reportf(" -asymm\n");
+ reportf(" -rcheck\n");
+ reportf(" -grow = <num> [ >0 ]\n");
+ reportf(" -polarity-mode = {true,false,rnd}\n");
+ reportf(" -decay = <num> [ 0 - 1 ]\n");
+ reportf(" -rnd-freq = <num> [ 0 - 1 ]\n");
+ reportf(" -dimacs = <output-file>\n");
+ reportf(" -verbosity = {0,1,2}\n");
+ reportf("\n");
+}
+
+typedef enum { pre_none, pre_once, pre_repeat } preprocessMode;
+
+const char* hasPrefix(const char* str, const char* prefix)
+{
+ int len = strlen(prefix);
+ if (strncmp(str, prefix, len) == 0)
+ return str + len;
+ else
+ return NULL;
+}
+
+
+int main(int argc, char** argv)
+{
+ reportf("This is MiniSat 2.0 beta\n");
+#if defined(__linux__)
+ fpu_control_t oldcw, newcw;
+ _FPU_GETCW(oldcw); newcw = (oldcw & ~_FPU_EXTENDED) | _FPU_DOUBLE; _FPU_SETCW(newcw);
+ reportf("WARNING: for repeatability, setting FPU to use double precision\n");
+#endif
+ preprocessMode pre = pre_once;
+ const char* dimacs = NULL;
+ const char* freeze = NULL;
+ SimpSolver S;
+ S.verbosity = 1;
+
+ // This just grew and grew, and I didn't have time to do sensible argument parsing yet :)
+ //
+ int i, j;
+ const char* value;
+ for (i = j = 0; i < argc; i++){
+ if ((value = hasPrefix(argv[i], "-polarity-mode="))){
+ if (strcmp(value, "true") == 0)
+ S.polarity_mode = Solver::polarity_true;
+ else if (strcmp(value, "false") == 0)
+ S.polarity_mode = Solver::polarity_false;
+ else if (strcmp(value, "rnd") == 0)
+ S.polarity_mode = Solver::polarity_rnd;
+ else{
+ reportf("ERROR! unknown polarity-mode %s\n", value);
+ exit(0); }
+
+ }else if ((value = hasPrefix(argv[i], "-rnd-freq="))){
+ double rnd;
+ if (sscanf(value, "%lf", &rnd) <= 0 || rnd < 0 || rnd > 1){
+ reportf("ERROR! illegal rnd-freq constant %s\n", value);
+ exit(0); }
+ S.random_var_freq = rnd;
+
+ }else if ((value = hasPrefix(argv[i], "-decay="))){
+ double decay;
+ if (sscanf(value, "%lf", &decay) <= 0 || decay <= 0 || decay > 1){
+ reportf("ERROR! illegal decay constant %s\n", value);
+ exit(0); }
+ S.var_decay = 1 / decay;
+
+ }else if ((value = hasPrefix(argv[i], "-verbosity="))){
+ int verbosity = (int)strtol(value, NULL, 10);
+ if (verbosity == 0 && errno == EINVAL){
+ reportf("ERROR! illegal verbosity level %s\n", value);
+ exit(0); }
+ S.verbosity = verbosity;
+
+ }else if ((value = hasPrefix(argv[i], "-pre="))){
+ if (strcmp(value, "none") == 0)
+ pre = pre_none;
+ else if (strcmp(value, "once") == 0)
+ pre = pre_once;
+ else if (strcmp(value, "repeat") == 0){
+ pre = pre_repeat;
+ reportf("ERROR! preprocessing mode \"repeat\" is not supported at the moment.\n");
+ exit(0);
+ }else{
+ reportf("ERROR! unknown preprocessing mode %s\n", value);
+ exit(0); }
+ }else if (strcmp(argv[i], "-asymm") == 0){
+ S.asymm_mode = true;
+ }else if (strcmp(argv[i], "-rcheck") == 0){
+ S.redundancy_check = true;
+ }else if ((value = hasPrefix(argv[i], "-grow="))){
+ int grow = (int)strtol(value, NULL, 10);
+ if (grow == 0 && errno == EINVAL){
+ reportf("ERROR! illegal grow constant %s\n", &argv[i][6]);
+ exit(0); }
+ S.grow = grow;
+ }else if ((value = hasPrefix(argv[i], "-dimacs="))){
+ dimacs = value;
+ }else if ((value = hasPrefix(argv[i], "-freeze="))){
+ freeze = value;
+ }else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "-help") == 0){
+ printUsage(argv);
+ exit(0);
+ }else if (strncmp(argv[i], "-", 1) == 0){
+ reportf("ERROR! unknown flag %s\n", argv[i]);
+ exit(0);
+ }else
+ argv[j++] = argv[i];
+ }
+ argc = j;
+
+ double cpu_time = cpuTime();
+
+ if (pre == pre_none)
+ S.eliminate(true);
+
+ solver = &S;
+ signal(SIGINT,SIGINT_handler);
+ signal(SIGHUP,SIGINT_handler);
+
+ if (argc == 1)
+ reportf("Reading from standard input... Use '-h' or '--help' for help.\n");
+
+ gzFile in = (argc == 1) ? gzdopen(0, "rb") : gzopen(argv[1], "rb");
+ if (in == NULL)
+ reportf("ERROR! Could not open file: %s\n", argc == 1 ? "<stdin>" : argv[1]), exit(1);
+
+ reportf("============================[ Problem Statistics ]=============================\n");
+ reportf("| |\n");
+
+ parse_DIMACS(in, S);
+ gzclose(in);
+ FILE* res = (argc >= 3) ? fopen(argv[2], "wb") : NULL;
+
+
+ double parse_time = cpuTime() - cpu_time;
+ reportf("| Parsing time: %-12.2f s |\n", parse_time);
+
+ /*HACK: Freeze variables*/
+ if (freeze != NULL && pre != pre_none){
+ int count = 0;
+ FILE* in = fopen(freeze, "rb");
+ for(;;){
+ Var x;
+ fscanf(in, "%d", &x);
+ if (x == 0) break;
+ x--;
+
+ /**/assert(S.n_occ[toInt(Lit(x))] + S.n_occ[toInt(~Lit(x))] != 0);
+ /**/assert(S.value(x) == l_Undef);
+ S.setFrozen(x, true);
+ count++;
+ }
+ fclose(in);
+ reportf("| Frozen vars : %-12.0f |\n", (double)count);
+ }
+ /*END*/
+
+ if (!S.simplify()){
+ reportf("Solved by unit propagation\n");
+ if (res != NULL) fprintf(res, "UNSAT\n"), fclose(res);
+ printf("UNSATISFIABLE\n");
+ exit(20);
+ }
+
+ if (dimacs){
+ if (pre != pre_none)
+ S.eliminate(true);
+ reportf("==============================[ Writing DIMACS ]===============================\n");
+ S.toDimacs(dimacs);
+ printStats(S);
+ exit(0);
+ }else{
+ bool ret = S.solve(true, true);
+ printStats(S);
+ reportf("\n");
+
+ printf(ret ? "SATISFIABLE\n" : "UNSATISFIABLE\n");
+ if (res != NULL){
+ if (ret){
+ fprintf(res, "SAT\n");
+ for (int i = 0; i < S.nVars(); i++)
+ if (S.model[i] != l_Undef)
+ fprintf(res, "%s%s%d", (i==0)?"":" ", (S.model[i]==l_True)?"":"-", i+1);
+ fprintf(res, " 0\n");
+ }else
+ fprintf(res, "UNSAT\n");
+ fclose(res);
+ }
+#ifdef NDEBUG
+ exit(ret ? 10 : 20); // (faster than "return", which will invoke the destructor for 'Solver')
+#endif
+ }
+
+}
--- /dev/null
+MTL = ../mtl
+CORE = ../core
+CHDRS = $(wildcard *.h) $(wildcard $(MTL)/*.h)
+EXEC = minisat
+CFLAGS = -I$(MTL) -I$(CORE) -Wall -ffloat-store
+LFLAGS = -lz
+
+CSRCS = $(wildcard *.C)
+COBJS = $(addsuffix .o, $(basename $(CSRCS))) $(CORE)/Solver.o
+
+include ../mtl/template.mk
--- /dev/null
+/************************************************************************************[SimpSolver.C]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include "Sort.h"
+#include "SimpSolver.h"
+
+
+//=================================================================================================
+// Constructor/Destructor:
+
+
+SimpSolver::SimpSolver() :
+ grow (0)
+ , asymm_mode (false)
+ , redundancy_check (false)
+ , merges (0)
+ , asymm_lits (0)
+ , remembered_clauses (0)
+ , elimorder (1)
+ , use_simplification (true)
+ , elim_heap (ElimLt(n_occ))
+ , bwdsub_assigns (0)
+{
+ vec<Lit> dummy(1,lit_Undef);
+ bwdsub_tmpunit = Clause_new(dummy);
+ remove_satisfied = false;
+}
+
+
+SimpSolver::~SimpSolver()
+{
+ free(bwdsub_tmpunit);
+
+ // NOTE: elimtable.size() might be lower than nVars() at the moment
+ for (int i = 0; i < elimtable.size(); i++)
+ for (int j = 0; j < elimtable[i].eliminated.size(); j++)
+ free(elimtable[i].eliminated[j]);
+}
+
+
+Var SimpSolver::newVar(bool sign, bool dvar) {
+ Var v = Solver::newVar(sign, dvar);
+
+ if (use_simplification){
+ n_occ .push(0);
+ n_occ .push(0);
+ occurs .push();
+ frozen .push((char)false);
+ touched .push(0);
+ elim_heap.insert(v);
+ elimtable.push();
+ }
+ return v; }
+
+
+
+bool SimpSolver::solve(const vec<Lit>& assumps, bool do_simp, bool turn_off_simp) {
+ vec<Var> extra_frozen;
+ bool result = true;
+
+ do_simp &= use_simplification;
+
+ if (do_simp){
+ // Assumptions must be temporarily frozen to run variable elimination:
+ for (int i = 0; i < assumps.size(); i++){
+ Var v = var(assumps[i]);
+
+ // If an assumption has been eliminated, remember it.
+ if (isEliminated(v))
+ remember(v);
+
+ if (!frozen[v]){
+ // Freeze and store.
+ setFrozen(v, true);
+ extra_frozen.push(v);
+ } }
+
+ result = eliminate(turn_off_simp);
+ }
+
+ if (result)
+ result = Solver::solve(assumps);
+
+ if (result) {
+ extendModel();
+#ifndef NDEBUG
+ verifyModel();
+#endif
+ }
+
+ if (do_simp)
+ // Unfreeze the assumptions that were frozen:
+ for (int i = 0; i < extra_frozen.size(); i++)
+ setFrozen(extra_frozen[i], false);
+
+ return result;
+}
+
+
+
+bool SimpSolver::addClause(vec<Lit>& ps)
+{
+ for (int i = 0; i < ps.size(); i++)
+ if (isEliminated(var(ps[i])))
+ remember(var(ps[i]));
+
+ int nclauses = clauses.size();
+
+ if (redundancy_check && implied(ps))
+ return true;
+
+ if (!Solver::addClause(ps))
+ return false;
+
+ if (use_simplification && clauses.size() == nclauses + 1){
+ Clause& c = *clauses.last();
+
+ subsumption_queue.insert(&c);
+
+ for (int i = 0; i < c.size(); i++){
+ assert(occurs.size() > var(c[i]));
+ assert(!find(occurs[var(c[i])], &c));
+
+ occurs[var(c[i])].push(&c);
+ n_occ[toInt(c[i])]++;
+ touched[var(c[i])] = 1;
+ assert(elimtable[var(c[i])].order == 0);
+ if (elim_heap.inHeap(var(c[i])))
+ elim_heap.increase_(var(c[i]));
+ }
+ }
+
+ return true;
+}
+
+
+void SimpSolver::removeClause(Clause& c)
+{
+ assert(!c.learnt());
+
+ if (use_simplification)
+ for (int i = 0; i < c.size(); i++){
+ n_occ[toInt(c[i])]--;
+ updateElimHeap(var(c[i]));
+ }
+
+ detachClause(c);
+ c.mark(1);
+}
+
+
+bool SimpSolver::strengthenClause(Clause& c, Lit l)
+{
+ assert(decisionLevel() == 0);
+ assert(c.mark() == 0);
+ assert(!c.learnt());
+ assert(find(watches[toInt(~c[0])], &c));
+ assert(find(watches[toInt(~c[1])], &c));
+
+ // FIX: this is too inefficient but would be nice to have (properly implemented)
+ // if (!find(subsumption_queue, &c))
+ subsumption_queue.insert(&c);
+
+ // If l is watched, delete it from watcher list and watch a new literal
+ if (c[0] == l || c[1] == l){
+ Lit other = c[0] == l ? c[1] : c[0];
+ if (c.size() == 2){
+ removeClause(c);
+ c.strengthen(l);
+ }else{
+ c.strengthen(l);
+ remove(watches[toInt(~l)], &c);
+
+ // Add a watch for the correct literal
+ watches[toInt(~(c[1] == other ? c[0] : c[1]))].push(&c);
+
+ // !! this version assumes that remove does not change the order !!
+ //watches[toInt(~c[1])].push(&c);
+ clauses_literals -= 1;
+ }
+ }
+ else{
+ c.strengthen(l);
+ clauses_literals -= 1;
+ }
+
+ // if subsumption-indexing is active perform the necessary updates
+ if (use_simplification){
+ remove(occurs[var(l)], &c);
+ n_occ[toInt(l)]--;
+ updateElimHeap(var(l));
+ }
+
+ return c.size() == 1 ? enqueue(c[0]) && propagate() == NULL : true;
+}
+
+
+// Returns FALSE if clause is always satisfied ('out_clause' should not be used).
+bool SimpSolver::merge(const Clause& _ps, const Clause& _qs, Var v, vec<Lit>& out_clause)
+{
+ merges++;
+ out_clause.clear();
+
+ bool ps_smallest = _ps.size() < _qs.size();
+ const Clause& ps = ps_smallest ? _qs : _ps;
+ const Clause& qs = ps_smallest ? _ps : _qs;
+
+ for (int i = 0; i < qs.size(); i++){
+ if (var(qs[i]) != v){
+ for (int j = 0; j < ps.size(); j++)
+ if (var(ps[j]) == var(qs[i]))
+ if (ps[j] == ~qs[i])
+ return false;
+ else
+ goto next;
+ out_clause.push(qs[i]);
+ }
+ next:;
+ }
+
+ for (int i = 0; i < ps.size(); i++)
+ if (var(ps[i]) != v)
+ out_clause.push(ps[i]);
+
+ return true;
+}
+
+
+// Returns FALSE if clause is always satisfied.
+bool SimpSolver::merge(const Clause& _ps, const Clause& _qs, Var v)
+{
+ merges++;
+
+ bool ps_smallest = _ps.size() < _qs.size();
+ const Clause& ps = ps_smallest ? _qs : _ps;
+ const Clause& qs = ps_smallest ? _ps : _qs;
+ const Lit* __ps = (const Lit*)ps;
+ const Lit* __qs = (const Lit*)qs;
+
+ for (int i = 0; i < qs.size(); i++){
+ if (var(__qs[i]) != v){
+ for (int j = 0; j < ps.size(); j++)
+ if (var(__ps[j]) == var(__qs[i]))
+ if (__ps[j] == ~__qs[i])
+ return false;
+ else
+ goto next;
+ }
+ next:;
+ }
+
+ return true;
+}
+
+
+void SimpSolver::gatherTouchedClauses()
+{
+ //fprintf(stderr, "Gathering clauses for backwards subsumption\n");
+ int ntouched = 0;
+ for (int i = 0; i < touched.size(); i++)
+ if (touched[i]){
+ const vec<Clause*>& cs = getOccurs(i);
+ ntouched++;
+ for (int j = 0; j < cs.size(); j++)
+ if (cs[j]->mark() == 0){
+ subsumption_queue.insert(cs[j]);
+ cs[j]->mark(2);
+ }
+ touched[i] = 0;
+ }
+
+ //fprintf(stderr, "Touched variables %d of %d yields %d clauses to check\n", ntouched, touched.size(), clauses.size());
+ for (int i = 0; i < subsumption_queue.size(); i++)
+ subsumption_queue[i]->mark(0);
+}
+
+
+bool SimpSolver::implied(const vec<Lit>& c)
+{
+ assert(decisionLevel() == 0);
+
+ trail_lim.push(trail.size());
+ for (int i = 0; i < c.size(); i++)
+ if (value(c[i]) == l_True){
+ cancelUntil(0);
+ return false;
+ }else if (value(c[i]) != l_False){
+ assert(value(c[i]) == l_Undef);
+ uncheckedEnqueue(~c[i]);
+ }
+
+ bool result = propagate() != NULL;
+ cancelUntil(0);
+ return result;
+}
+
+
+// Backward subsumption + backward subsumption resolution
+bool SimpSolver::backwardSubsumptionCheck(bool verbose)
+{
+ int cnt = 0;
+ int subsumed = 0;
+ int deleted_literals = 0;
+ assert(decisionLevel() == 0);
+
+ while (subsumption_queue.size() > 0 || bwdsub_assigns < trail.size()){
+
+ // Check top-level assignments by creating a dummy clause and placing it in the queue:
+ if (subsumption_queue.size() == 0 && bwdsub_assigns < trail.size()){
+ Lit l = trail[bwdsub_assigns++];
+ (*bwdsub_tmpunit)[0] = l;
+ bwdsub_tmpunit->calcAbstraction();
+ assert(bwdsub_tmpunit->mark() == 0);
+ subsumption_queue.insert(bwdsub_tmpunit); }
+
+ Clause& c = *subsumption_queue.peek(); subsumption_queue.pop();
+
+ if (c.mark()) continue;
+
+ if (verbose && verbosity >= 2 && cnt++ % 1000 == 0)
+ reportf("subsumption left: %10d (%10d subsumed, %10d deleted literals)\r", subsumption_queue.size(), subsumed, deleted_literals);
+
+ assert(c.size() > 1 || value(c[0]) == l_True); // Unit-clauses should have been propagated before this point.
+
+ // Find best variable to scan:
+ Var best = var(c[0]);
+ for (int i = 1; i < c.size(); i++)
+ if (occurs[var(c[i])].size() < occurs[best].size())
+ best = var(c[i]);
+
+ // Search all candidates:
+ vec<Clause*>& _cs = getOccurs(best);
+ Clause** cs = (Clause**)_cs;
+
+ for (int j = 0; j < _cs.size(); j++)
+ if (c.mark())
+ break;
+ else if (!cs[j]->mark() && cs[j] != &c){
+ Lit l = c.subsumes(*cs[j]);
+
+ if (l == lit_Undef)
+ subsumed++, removeClause(*cs[j]);
+ else if (l != lit_Error){
+ deleted_literals++;
+
+ if (!strengthenClause(*cs[j], ~l))
+ return false;
+
+ // Did current candidate get deleted from cs? Then check candidate at index j again:
+ if (var(l) == best)
+ j--;
+ }
+ }
+ }
+
+ return true;
+}
+
+
+bool SimpSolver::asymm(Var v, Clause& c)
+{
+ assert(decisionLevel() == 0);
+
+ if (c.mark() || satisfied(c)) return true;
+
+ trail_lim.push(trail.size());
+ Lit l = lit_Undef;
+ for (int i = 0; i < c.size(); i++)
+ if (var(c[i]) != v && value(c[i]) != l_False)
+ uncheckedEnqueue(~c[i]);
+ else
+ l = c[i];
+
+ if (propagate() != NULL){
+ cancelUntil(0);
+ asymm_lits++;
+ if (!strengthenClause(c, l))
+ return false;
+ }else
+ cancelUntil(0);
+
+ return true;
+}
+
+
+bool SimpSolver::asymmVar(Var v)
+{
+ assert(!frozen[v]);
+ assert(use_simplification);
+
+ vec<Clause*> pos, neg;
+ const vec<Clause*>& cls = getOccurs(v);
+
+ if (value(v) != l_Undef || cls.size() == 0)
+ return true;
+
+ for (int i = 0; i < cls.size(); i++)
+ if (!asymm(v, *cls[i]))
+ return false;
+
+ return backwardSubsumptionCheck();
+}
+
+
+void SimpSolver::verifyModel()
+{
+ bool failed = false;
+ int cnt = 0;
+ // NOTE: elimtable.size() might be lower than nVars() at the moment
+ for (int i = 0; i < elimtable.size(); i++)
+ if (elimtable[i].order > 0)
+ for (int j = 0; j < elimtable[i].eliminated.size(); j++){
+ cnt++;
+ Clause& c = *elimtable[i].eliminated[j];
+ for (int k = 0; k < c.size(); k++)
+ if (modelValue(c[k]) == l_True)
+ goto next;
+
+ reportf("unsatisfied clause: ");
+ printClause(*elimtable[i].eliminated[j]);
+ reportf("\n");
+ failed = true;
+ next:;
+ }
+
+ assert(!failed);
+ reportf("Verified %d eliminated clauses.\n", cnt);
+}
+
+
+bool SimpSolver::eliminateVar(Var v, bool fail)
+{
+ if (!fail && asymm_mode && !asymmVar(v)) return false;
+
+ const vec<Clause*>& cls = getOccurs(v);
+
+// if (value(v) != l_Undef || cls.size() == 0) return true;
+ if (value(v) != l_Undef) return true;
+
+ // Split the occurrences into positive and negative:
+ vec<Clause*> pos, neg;
+ for (int i = 0; i < cls.size(); i++)
+ (find(*cls[i], Lit(v)) ? pos : neg).push(cls[i]);
+
+ // Check if number of clauses decreases:
+ int cnt = 0;
+ for (int i = 0; i < pos.size(); i++)
+ for (int j = 0; j < neg.size(); j++)
+ if (merge(*pos[i], *neg[j], v) && ++cnt > cls.size() + grow)
+ return true;
+
+ // Delete and store old clauses:
+ setDecisionVar(v, false);
+ elimtable[v].order = elimorder++;
+ assert(elimtable[v].eliminated.size() == 0);
+ for (int i = 0; i < cls.size(); i++){
+ elimtable[v].eliminated.push(Clause_new(*cls[i]));
+ removeClause(*cls[i]); }
+
+ // Produce clauses in cross product:
+ int top = clauses.size();
+ vec<Lit> resolvent;
+ for (int i = 0; i < pos.size(); i++)
+ for (int j = 0; j < neg.size(); j++)
+ if (merge(*pos[i], *neg[j], v, resolvent) && !addClause(resolvent))
+ return false;
+
+ // DEBUG: For checking that a clause set is saturated with respect to variable elimination.
+ // If the clause set is expected to be saturated at this point, this constitutes an
+ // error.
+ if (fail){
+ reportf("eliminated var %d, %d <= %d\n", v+1, cnt, cls.size());
+ reportf("previous clauses:\n");
+ for (int i = 0; i < cls.size(); i++){
+ printClause(*cls[i]); reportf("\n"); }
+ reportf("new clauses:\n");
+ for (int i = top; i < clauses.size(); i++){
+ printClause(*clauses[i]); reportf("\n"); }
+ assert(0); }
+
+ return backwardSubsumptionCheck();
+}
+
+
+void SimpSolver::remember(Var v)
+{
+ assert(decisionLevel() == 0);
+ assert(isEliminated(v));
+
+ vec<Lit> clause;
+
+ // Re-activate variable:
+ elimtable[v].order = 0;
+ setDecisionVar(v, true); // Not good if the variable wasn't a decision variable before. Not sure how to fix this right now.
+
+ if (use_simplification)
+ updateElimHeap(v);
+
+ // Reintroduce all old clauses which may implicitly remember other clauses:
+ for (int i = 0; i < elimtable[v].eliminated.size(); i++){
+ Clause& c = *elimtable[v].eliminated[i];
+ clause.clear();
+ for (int j = 0; j < c.size(); j++)
+ clause.push(c[j]);
+
+ remembered_clauses++;
+ check(addClause(clause));
+ free(&c);
+ }
+
+ elimtable[v].eliminated.clear();
+}
+
+
+void SimpSolver::extendModel()
+{
+ vec<Var> vs;
+
+ // NOTE: elimtable.size() might be lower than nVars() at the moment
+ for (int v = 0; v < elimtable.size(); v++)
+ if (elimtable[v].order > 0)
+ vs.push(v);
+
+ sort(vs, ElimOrderLt(elimtable));
+
+ for (int i = 0; i < vs.size(); i++){
+ Var v = vs[i];
+ Lit l = lit_Undef;
+
+ for (int j = 0; j < elimtable[v].eliminated.size(); j++){
+ Clause& c = *elimtable[v].eliminated[j];
+
+ for (int k = 0; k < c.size(); k++)
+ if (var(c[k]) == v)
+ l = c[k];
+ else if (modelValue(c[k]) != l_False)
+ goto next;
+
+ assert(l != lit_Undef);
+ model[v] = lbool(!sign(l));
+ break;
+
+ next:;
+ }
+
+ if (model[v] == l_Undef)
+ model[v] = l_True;
+ }
+}
+
+
+bool SimpSolver::eliminate(bool turn_off_elim)
+{
+ if (!ok || !use_simplification)
+ return ok;
+
+ // Main simplification loop:
+ //assert(subsumption_queue.size() == 0);
+ //gatherTouchedClauses();
+ while (subsumption_queue.size() > 0 || elim_heap.size() > 0){
+
+ //fprintf(stderr, "subsumption phase: (%d)\n", subsumption_queue.size());
+ if (!backwardSubsumptionCheck(true))
+ return false;
+
+ //fprintf(stderr, "elimination phase:\n (%d)", elim_heap.size());
+ for (int cnt = 0; !elim_heap.empty(); cnt++){
+ Var elim = elim_heap.removeMin();
+
+ if (verbosity >= 2 && cnt % 100 == 0)
+ reportf("elimination left: %10d\r", elim_heap.size());
+
+ if (!frozen[elim] && !eliminateVar(elim))
+ return false;
+ }
+
+ assert(subsumption_queue.size() == 0);
+ gatherTouchedClauses();
+ }
+
+ // Cleanup:
+ cleanUpClauses();
+ order_heap.filter(VarFilter(*this));
+
+#ifdef INVARIANTS
+ // Check that no more subsumption is possible:
+ reportf("Checking that no more subsumption is possible\n");
+ for (int i = 0; i < clauses.size(); i++){
+ if (i % 1000 == 0)
+ reportf("left %10d\r", clauses.size() - i);
+
+ assert(clauses[i]->mark() == 0);
+ for (int j = 0; j < i; j++)
+ assert(clauses[i]->subsumes(*clauses[j]) == lit_Error);
+ }
+ reportf("done.\n");
+
+ // Check that no more elimination is possible:
+ reportf("Checking that no more elimination is possible\n");
+ for (int i = 0; i < nVars(); i++)
+ if (!frozen[i]) eliminateVar(i, true);
+ reportf("done.\n");
+ checkLiteralCount();
+#endif
+
+ // If no more simplification is needed, free all simplification-related data structures:
+ if (turn_off_elim){
+ use_simplification = false;
+ touched.clear(true);
+ occurs.clear(true);
+ n_occ.clear(true);
+ subsumption_queue.clear(true);
+ elim_heap.clear(true);
+ remove_satisfied = true;
+ }
+
+
+ return true;
+}
+
+
+void SimpSolver::cleanUpClauses()
+{
+ int i , j;
+ vec<Var> dirty;
+ for (i = 0; i < clauses.size(); i++)
+ if (clauses[i]->mark() == 1){
+ Clause& c = *clauses[i];
+ for (int k = 0; k < c.size(); k++)
+ if (!seen[var(c[k])]){
+ seen[var(c[k])] = 1;
+ dirty.push(var(c[k]));
+ } }
+
+ for (i = 0; i < dirty.size(); i++){
+ cleanOcc(dirty[i]);
+ seen[dirty[i]] = 0; }
+
+ for (i = j = 0; i < clauses.size(); i++)
+ if (clauses[i]->mark() == 1)
+ free(clauses[i]);
+ else
+ clauses[j++] = clauses[i];
+ clauses.shrink(i - j);
+}
+
+
+//=================================================================================================
+// Convert to DIMACS:
+
+
+void SimpSolver::toDimacs(FILE* f, Clause& c)
+{
+ if (satisfied(c)) return;
+
+ for (int i = 0; i < c.size(); i++)
+ if (value(c[i]) != l_False)
+ fprintf(f, "%s%d ", sign(c[i]) ? "-" : "", var(c[i])+1);
+ fprintf(f, "0\n");
+}
+
+
+void SimpSolver::toDimacs(const char* file)
+{
+ assert(decisionLevel() == 0);
+ FILE* f = fopen(file, "wr");
+ if (f != NULL){
+
+ // Cannot use removeClauses here because it is not safe
+ // to deallocate them at this point. Could be improved.
+ int cnt = 0;
+ for (int i = 0; i < clauses.size(); i++)
+ if (!satisfied(*clauses[i]))
+ cnt++;
+
+ fprintf(f, "p cnf %d %d\n", nVars(), cnt);
+
+ for (int i = 0; i < clauses.size(); i++)
+ toDimacs(f, *clauses[i]);
+
+ fprintf(stderr, "Wrote %d clauses...\n", clauses.size());
+ }else
+ fprintf(stderr, "could not open file %s\n", file);
+}
--- /dev/null
+/************************************************************************************[SimpSolver.h]
+MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef SimpSolver_h
+#define SimpSolver_h
+
+#include <cstdio>
+
+#include "Queue.h"
+#include "Solver.h"
+
+
+class SimpSolver : public Solver {
+ public:
+ // Constructor/Destructor:
+ //
+ SimpSolver();
+ ~SimpSolver();
+
+ // Problem specification:
+ //
+ Var newVar (bool polarity = true, bool dvar = true);
+ bool addClause (vec<Lit>& ps);
+
+ // Variable mode:
+ //
+ void setFrozen (Var v, bool b); // If a variable is frozen it will not be eliminated.
+
+ // Solving:
+ //
+ bool solve (const vec<Lit>& assumps, bool do_simp = true, bool turn_off_simp = false);
+ bool solve (bool do_simp = true, bool turn_off_simp = false);
+ bool eliminate (bool turn_off_elim = false); // Perform variable elimination based simplification.
+
+ // Generate a (possibly simplified) DIMACS file:
+ //
+ void toDimacs (const char* file);
+
+ // Mode of operation:
+ //
+ int grow; // Allow a variable elimination step to grow by a number of clauses (default to zero).
+ bool asymm_mode; // Shrink clauses by asymmetric branching.
+ bool redundancy_check; // Check if a clause is already implied. Prett costly, and subsumes subsumptions :)
+
+ // Statistics:
+ //
+ int merges;
+ int asymm_lits;
+ int remembered_clauses;
+
+// protected:
+ public:
+
+ // Helper structures:
+ //
+ struct ElimData {
+ int order; // 0 means not eliminated, >0 gives an index in the elimination order
+ vec<Clause*> eliminated;
+ ElimData() : order(0) {} };
+
+ struct ElimOrderLt {
+ const vec<ElimData>& elimtable;
+ ElimOrderLt(const vec<ElimData>& et) : elimtable(et) {}
+ bool operator()(Var x, Var y) { return elimtable[x].order > elimtable[y].order; } };
+
+ struct ElimLt {
+ const vec<int>& n_occ;
+ ElimLt(const vec<int>& no) : n_occ(no) {}
+ int cost (Var x) const { return n_occ[toInt(Lit(x))] * n_occ[toInt(~Lit(x))]; }
+ bool operator()(Var x, Var y) const { return cost(x) < cost(y); } };
+
+
+ // Solver state:
+ //
+ int elimorder;
+ bool use_simplification;
+ vec<ElimData> elimtable;
+ vec<char> touched;
+ vec<vec<Clause*> > occurs;
+ vec<int> n_occ;
+ Heap<ElimLt> elim_heap;
+ Queue<Clause*> subsumption_queue;
+ vec<char> frozen;
+ int bwdsub_assigns;
+
+ // Temporaries:
+ //
+ Clause* bwdsub_tmpunit;
+
+ // Main internal methods:
+ //
+ bool asymm (Var v, Clause& c);
+ bool asymmVar (Var v);
+ void updateElimHeap (Var v);
+ void cleanOcc (Var v);
+ vec<Clause*>& getOccurs (Var x);
+ void gatherTouchedClauses ();
+ bool merge (const Clause& _ps, const Clause& _qs, Var v, vec<Lit>& out_clause);
+ bool merge (const Clause& _ps, const Clause& _qs, Var v);
+ bool backwardSubsumptionCheck (bool verbose = false);
+ bool eliminateVar (Var v, bool fail = false);
+ void remember (Var v);
+ void extendModel ();
+ void verifyModel ();
+
+ void removeClause (Clause& c);
+ bool strengthenClause (Clause& c, Lit l);
+ void cleanUpClauses ();
+ bool implied (const vec<Lit>& c);
+ void toDimacs (FILE* f, Clause& c);
+ bool isEliminated (Var v) const;
+
+};
+
+
+//=================================================================================================
+// Implementation of inline methods:
+
+inline void SimpSolver::updateElimHeap(Var v) {
+ if (elimtable[v].order == 0)
+ elim_heap.update(v); }
+
+inline void SimpSolver::cleanOcc(Var v) {
+ assert(use_simplification);
+ Clause **begin = (Clause**)occurs[v];
+ Clause **end = begin + occurs[v].size();
+ Clause **i, **j;
+ for (i = begin, j = end; i < j; i++)
+ if ((*i)->mark() == 1){
+ *i = *(--j);
+ i--;
+ }
+ //occurs[v].shrink_(end - j); // This seems slower. Why?!
+ occurs[v].shrink(end - j);
+}
+
+inline vec<Clause*>& SimpSolver::getOccurs(Var x) {
+ cleanOcc(x); return occurs[x]; }
+
+inline bool SimpSolver::isEliminated (Var v) const { return v < elimtable.size() && elimtable[v].order != 0; }
+inline void SimpSolver::setFrozen (Var v, bool b) { frozen[v] = (char)b; if (b) { updateElimHeap(v); } }
+inline bool SimpSolver::solve (bool do_simp, bool turn_off_simp) { vec<Lit> tmp; return solve(tmp, do_simp, turn_off_simp); }
+
+//=================================================================================================
+#endif
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