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[gcc.git] / libstdc++-v3 / doc / html / manual / policy_data_structures_using.html
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3 <html xmlns="http://www.w3.org/1999/xhtml"><head><title>Using</title><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"/><meta name="keywords" content="&#10;&#9;ISO C++&#10; , &#10;&#9;policy&#10; , &#10;&#9;container&#10; , &#10;&#9;data&#10; , &#10;&#9;structure&#10; , &#10;&#9;associated&#10; , &#10;&#9;tree&#10; , &#10;&#9;trie&#10; , &#10;&#9;hash&#10; , &#10;&#9;metaprogramming&#10; "/><meta name="keywords" content="&#10; ISO C++&#10; , &#10; library&#10; "/><meta name="keywords" content="&#10; ISO C++&#10; , &#10; runtime&#10; , &#10; library&#10; "/><link rel="home" href="../index.html" title="The GNU C++ Library"/><link rel="up" href="policy_data_structures.html" title="Chapter 22. Policy-Based Data Structures"/><link rel="prev" href="policy_data_structures.html" title="Chapter 22. Policy-Based Data Structures"/><link rel="next" href="policy_data_structures_design.html" title="Design"/></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Using</th></tr><tr><td align="left"><a accesskey="p" href="policy_data_structures.html">Prev</a> </td><th width="60%" align="center">Chapter 22. Policy-Based Data Structures</th><td align="right"> <a accesskey="n" href="policy_data_structures_design.html">Next</a></td></tr></table><hr/></div><div class="section" title="Using"><div class="titlepage"><div><div><h2 class="title"><a id="containers.pbds.using"/>Using</h2></div></div></div><div class="section" title="Prerequisites"><div class="titlepage"><div><div><h3 class="title"><a id="pbds.using.prereq"/>Prerequisites</h3></div></div></div><p>The library contains only header files, and does not require any
4 other libraries except the standard C++ library . All classes are
5 defined in namespace <code class="code">__gnu_pbds</code>. The library internally
6 uses macros beginning with <code class="code">PB_DS</code>, but
7 <code class="code">#undef</code>s anything it <code class="code">#define</code>s (except for
8 header guards). Compiling the library in an environment where macros
9 beginning in <code class="code">PB_DS</code> are defined, may yield unpredictable
10 results in compilation, execution, or both.</p><p>
11 Further dependencies are necessary to create the visual output
12 for the performance tests. To create these graphs, an
13 additional package is needed: <span class="command"><strong>pychart</strong></span>.
14 </p></div><div class="section" title="Organization"><div class="titlepage"><div><div><h3 class="title"><a id="pbds.using.organization"/>Organization</h3></div></div></div><p>
15 The various data structures are organized as follows.
16 </p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
17 Branch-Based
18 </p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
19 <code class="classname">basic_branch</code>
20 is an abstract base class for branched-based
21 associative-containers
22 </p></li><li class="listitem"><p>
23 <code class="classname">tree</code>
24 is a concrete base class for tree-based
25 associative-containers
26 </p></li><li class="listitem"><p>
27 <code class="classname">trie</code>
28 is a concrete base class trie-based
29 associative-containers
30 </p></li></ul></div></li><li class="listitem"><p>
31 Hash-Based
32 </p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
33 <code class="classname">basic_hash_table</code>
34 is an abstract base class for hash-based
35 associative-containers
36 </p></li><li class="listitem"><p>
37 <code class="classname">cc_hash_table</code>
38 is a concrete collision-chaining hash-based
39 associative-containers
40 </p></li><li class="listitem"><p>
41 <code class="classname">gp_hash_table</code>
42 is a concrete (general) probing hash-based
43 associative-containers
44 </p></li></ul></div></li><li class="listitem"><p>
45 List-Based
46 </p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
47 <code class="classname">list_update</code>
48 list-based update-policy associative container
49 </p></li></ul></div></li><li class="listitem"><p>
50 Heap-Based
51 </p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
52 <code class="classname">priority_queue</code>
53 A priority queue.
54 </p></li></ul></div></li></ul></div><p>
55 The hierarchy is composed naturally so that commonality is
56 captured by base classes. Thus <code class="function">operator[]</code>
57 is defined at the base of any hierarchy, since all derived
58 containers support it. Conversely <code class="function">split</code> is
59 defined in <code class="classname">basic_branch</code>, since only
60 tree-like containers support it.
61 </p><p>
62 In addition, there are the following diagnostics classes,
63 used to report errors specific to this library's data
64 structures.
65 </p><div class="figure"><a id="id476154"/><p class="title"><strong>Figure 22.7. Exception Hierarchy</strong></p><div class="figure-contents"><div class="mediaobject" style="text-align: center"><img src="../images/pbds_exception_hierarchy.png" style="text-align: middle" alt="Exception Hierarchy"/></div></div></div><br class="figure-break"/></div><div class="section" title="Tutorial"><div class="titlepage"><div><div><h3 class="title"><a id="pbds.using.tutorial"/>Tutorial</h3></div></div></div><div class="section" title="Basic Use"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.tutorial.basic"/>Basic Use</h4></div></div></div><p>
66 For the most part, the policy-based containers containers in
67 namespace <code class="literal">__gnu_pbds</code> have the same interface as
68 the equivalent containers in the standard C++ library, except for
69 the names used for the container classes themselves. For example,
70 this shows basic operations on a collision-chaining hash-based
71 container:
72 </p><pre class="programlisting">
73 #include &lt;ext/pb_ds/assoc_container.h&gt;
74
75 int main()
76 {
77 __gnu_pbds::cc_hash_table&lt;int, char&gt; c;
78 c[2] = 'b';
79 assert(c.find(1) == c.end());
80 };
81 </pre><p>
82 The container is called
83 <code class="classname">__gnu_pbds::cc_hash_table</code> instead of
84 <code class="classname">std::unordered_map</code>, since <span class="quote"><span class="quote">unordered
85 map</span></span> does not necessarily mean a hash-based map as implied by
86 the C++ library (C++11 or TR1). For example, list-based associative
87 containers, which are very useful for the construction of
88 "multimaps," are also unordered.
89 </p><p>This snippet shows a red-black tree based container:</p><pre class="programlisting">
90 #include &lt;ext/pb_ds/assoc_container.h&gt;
91
92 int main()
93 {
94 __gnu_pbds::tree&lt;int, char&gt; c;
95 c[2] = 'b';
96 assert(c.find(2) != c.end());
97 };
98 </pre><p>The container is called <code class="classname">tree</code> instead of
99 <code class="classname">map</code> since the underlying data structures are
100 being named with specificity.
101 </p><p>
102 The member function naming convention is to strive to be the same as
103 the equivalent member functions in other C++ standard library
104 containers. The familiar methods are unchanged:
105 <code class="function">begin</code>, <code class="function">end</code>,
106 <code class="function">size</code>, <code class="function">empty</code>, and
107 <code class="function">clear</code>.
108 </p><p>
109 This isn't to say that things are exactly as one would expect, given
110 the container requirments and interfaces in the C++ standard.
111 </p><p>
112 The names of containers' policies and policy accessors are
113 different then the usual. For example, if <span class="type">hash_type</span> is
114 some type of hash-based container, then</p><pre class="programlisting">
115 hash_type::hash_fn
116 </pre><p>
117 gives the type of its hash functor, and if <code class="varname">obj</code> is
118 some hash-based container object, then
119 </p><pre class="programlisting">
120 obj.get_hash_fn()
121 </pre><p>will return a reference to its hash-functor object.</p><p>
122 Similarly, if <span class="type">tree_type</span> is some type of tree-based
123 container, then
124 </p><pre class="programlisting">
125 tree_type::cmp_fn
126 </pre><p>
127 gives the type of its comparison functor, and if
128 <code class="varname">obj</code> is some tree-based container object,
129 then
130 </p><pre class="programlisting">
131 obj.get_cmp_fn()
132 </pre><p>will return a reference to its comparison-functor object.</p><p>
133 It would be nice to give names consistent with those in the existing
134 C++ standard (inclusive of TR1). Unfortunately, these standard
135 containers don't consistently name types and methods. For example,
136 <code class="classname">std::tr1::unordered_map</code> uses
137 <span class="type">hasher</span> for the hash functor, but
138 <code class="classname">std::map</code> uses <span class="type">key_compare</span> for
139 the comparison functor. Also, we could not find an accessor for
140 <code class="classname">std::tr1::unordered_map</code>'s hash functor, but
141 <code class="classname">std::map</code> uses <code class="classname">compare</code>
142 for accessing the comparison functor.
143 </p><p>
144 Instead, <code class="literal">__gnu_pbds</code> attempts to be internally
145 consistent, and uses standard-derived terminology if possible.
146 </p><p>
147 Another source of difference is in scope:
148 <code class="literal">__gnu_pbds</code> contains more types of associative
149 containers than the standard C++ library, and more opportunities
150 to configure these new containers, since different types of
151 associative containers are useful in different settings.
152 </p><p>
153 Namespace <code class="literal">__gnu_pbds</code> contains different classes for
154 hash-based containers, tree-based containers, trie-based containers,
155 and list-based containers.
156 </p><p>
157 Since associative containers share parts of their interface, they
158 are organized as a class hierarchy.
159 </p><p>Each type or method is defined in the most-common ancestor
160 in which it makes sense.
161 </p><p>For example, all associative containers support iteration
162 expressed in the following form:
163 </p><pre class="programlisting">
164 const_iterator
165 begin() const;
166
167 iterator
168 begin();
169
170 const_iterator
171 end() const;
172
173 iterator
174 end();
175 </pre><p>
176 But not all containers contain or use hash functors. Yet, both
177 collision-chaining and (general) probing hash-based associative
178 containers have a hash functor, so
179 <code class="classname">basic_hash_table</code> contains the interface:
180 </p><pre class="programlisting">
181 const hash_fn&amp;
182 get_hash_fn() const;
183
184 hash_fn&amp;
185 get_hash_fn();
186 </pre><p>
187 so all hash-based associative containers inherit the same
188 hash-functor accessor methods.
189 </p></div><div class="section" title="Configuring via Template Parameters"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.tutorial.configuring"/>
190 Configuring via Template Parameters
191 </h4></div></div></div><p>
192 In general, each of this library's containers is
193 parametrized by more policies than those of the standard library. For
194 example, the standard hash-based container is parametrized as
195 follows:
196 </p><pre class="programlisting">
197 template&lt;typename Key, typename Mapped, typename Hash,
198 typename Pred, typename Allocator, bool Cache_Hashe_Code&gt;
199 class unordered_map;
200 </pre><p>
201 and so can be configured by key type, mapped type, a functor
202 that translates keys to unsigned integral types, an equivalence
203 predicate, an allocator, and an indicator whether to store hash
204 values with each entry. this library's collision-chaining
205 hash-based container is parametrized as
206 </p><pre class="programlisting">
207 template&lt;typename Key, typename Mapped, typename Hash_Fn,
208 typename Eq_Fn, typename Comb_Hash_Fn,
209 typename Resize_Policy, bool Store_Hash
210 typename Allocator&gt;
211 class cc_hash_table;
212 </pre><p>
213 and so can be configured by the first four types of
214 <code class="classname">std::tr1::unordered_map</code>, then a
215 policy for translating the key-hash result into a position
216 within the table, then a policy by which the table resizes,
217 an indicator whether to store hash values with each entry,
218 and an allocator (which is typically the last template
219 parameter in standard containers).
220 </p><p>
221 Nearly all policy parameters have default values, so this
222 need not be considered for casual use. It is important to
223 note, however, that hash-based containers' policies can
224 dramatically alter their performance in different settings,
225 and that tree-based containers' policies can make them
226 useful for other purposes than just look-up.
227 </p><p>As opposed to associative containers, priority queues have
228 relatively few configuration options. The priority queue is
229 parametrized as follows:</p><pre class="programlisting">
230 template&lt;typename Value_Type, typename Cmp_Fn,typename Tag,
231 typename Allocator&gt;
232 class priority_queue;
233 </pre><p>The <code class="classname">Value_Type</code>, <code class="classname">Cmp_Fn</code>, and
234 <code class="classname">Allocator</code> parameters are the container's value type,
235 comparison-functor type, and allocator type, respectively;
236 these are very similar to the standard's priority queue. The
237 <code class="classname">Tag</code> parameter is different: there are a number of
238 pre-defined tag types corresponding to binary heaps, binomial
239 heaps, etc., and <code class="classname">Tag</code> should be instantiated
240 by one of them.</p><p>Note that as opposed to the
241 <code class="classname">std::priority_queue</code>,
242 <code class="classname">__gnu_pbds::priority_queue</code> is not a
243 sequence-adapter; it is a regular container.</p></div><div class="section" title="Querying Container Attributes"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.tutorial.traits"/>
244 Querying Container Attributes
245 </h4></div></div></div><p/><p>A containers underlying data structure
246 affect their performance; Unfortunately, they can also affect
247 their interface. When manipulating generically associative
248 containers, it is often useful to be able to statically
249 determine what they can support and what the cannot.
250 </p><p>Happily, the standard provides a good solution to a similar
251 problem - that of the different behavior of iterators. If
252 <code class="classname">It</code> is an iterator, then
253 </p><pre class="programlisting">
254 typename std::iterator_traits&lt;It&gt;::iterator_category
255 </pre><p>is one of a small number of pre-defined tag classes, and
256 </p><pre class="programlisting">
257 typename std::iterator_traits&lt;It&gt;::value_type
258 </pre><p>is the value type to which the iterator "points".</p><p>
259 Similarly, in this library, if <span class="type">C</span> is a
260 container, then <code class="classname">container_traits</code> is a
261 trait class that stores information about the kind of
262 container that is implemented.
263 </p><pre class="programlisting">
264 typename container_traits&lt;C&gt;::container_category
265 </pre><p>
266 is one of a small number of predefined tag structures that
267 uniquely identifies the type of underlying data structure.
268 </p><p>In most cases, however, the exact underlying data
269 structure is not really important, but what is important is
270 one of its other attributes: whether it guarantees storing
271 elements by key order, for example. For this one can
272 use</p><pre class="programlisting">
273 typename container_traits&lt;C&gt;::order_preserving
274 </pre><p>
275 Also,
276 </p><pre class="programlisting">
277 typename container_traits&lt;C&gt;::invalidation_guarantee
278 </pre><p>is the container's invalidation guarantee. Invalidation
279 guarantees are especially important regarding priority queues,
280 since in this library's design, iterators are practically the
281 only way to manipulate them.</p></div><div class="section" title="Point and Range Iteration"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.tutorial.point_range_iteration"/>
282 Point and Range Iteration
283 </h4></div></div></div><p/><p>This library differentiates between two types of methods
284 and iterators: point-type, and range-type. For example,
285 <code class="function">find</code> and <code class="function">insert</code> are point-type methods, since
286 they each deal with a specific element; their returned
287 iterators are point-type iterators. <code class="function">begin</code> and
288 <code class="function">end</code> are range-type methods, since they are not used to
289 find a specific element, but rather to go over all elements in
290 a container object; their returned iterators are range-type
291 iterators.
292 </p><p>Most containers store elements in an order that is
293 determined by their interface. Correspondingly, it is fine that
294 their point-type iterators are synonymous with their range-type
295 iterators. For example, in the following snippet
296 </p><pre class="programlisting">
297 std::for_each(c.find(1), c.find(5), foo);
298 </pre><p>
299 two point-type iterators (returned by <code class="function">find</code>) are used
300 for a range-type purpose - going over all elements whose key is
301 between 1 and 5.
302 </p><p>
303 Conversely, the above snippet makes no sense for
304 self-organizing containers - ones that order (and reorder)
305 their elements by implementation. It would be nice to have a
306 uniform iterator system that would allow the above snippet to
307 compile only if it made sense.
308 </p><p>
309 This could trivially be done by specializing
310 <code class="function">std::for_each</code> for the case of iterators returned by
311 <code class="classname">std::tr1::unordered_map</code>, but this would only solve the
312 problem for one algorithm and one container. Fundamentally, the
313 problem is that one can loop using a self-organizing
314 container's point-type iterators.
315 </p><p>
316 This library's containers define two families of
317 iterators: <span class="type">point_const_iterator</span> and
318 <span class="type">point_iterator</span> are the iterator types returned by
319 point-type methods; <span class="type">const_iterator</span> and
320 <span class="type">iterator</span> are the iterator types returned by range-type
321 methods.
322 </p><pre class="programlisting">
323 class &lt;- some container -&gt;
324 {
325 public:
326 ...
327
328 typedef &lt;- something -&gt; const_iterator;
329
330 typedef &lt;- something -&gt; iterator;
331
332 typedef &lt;- something -&gt; point_const_iterator;
333
334 typedef &lt;- something -&gt; point_iterator;
335
336 ...
337
338 public:
339 ...
340
341 const_iterator begin () const;
342
343 iterator begin();
344
345 point_const_iterator find(...) const;
346
347 point_iterator find(...);
348 };
349 </pre><p>For
350 containers whose interface defines sequence order , it
351 is very simple: point-type and range-type iterators are exactly
352 the same, which means that the above snippet will compile if it
353 is used for an order-preserving associative container.
354 </p><p>
355 For self-organizing containers, however, (hash-based
356 containers as a special example), the preceding snippet will
357 not compile, because their point-type iterators do not support
358 <code class="function">operator++</code>.
359 </p><p>In any case, both for order-preserving and self-organizing
360 containers, the following snippet will compile:
361 </p><pre class="programlisting">
362 typename Cntnr::point_iterator it = c.find(2);
363 </pre><p>
364 because a range-type iterator can always be converted to a
365 point-type iterator.
366 </p><p>Distingushing between iterator types also
367 raises the point that a container's iterators might have
368 different invalidation rules concerning their de-referencing
369 abilities and movement abilities. This now corresponds exactly
370 to the question of whether point-type and range-type iterators
371 are valid. As explained above, <code class="classname">container_traits</code> allows
372 querying a container for its data structure attributes. The
373 iterator-invalidation guarantees are certainly a property of
374 the underlying data structure, and so
375 </p><pre class="programlisting">
376 container_traits&lt;C&gt;::invalidation_guarantee
377 </pre><p>
378 gives one of three pre-determined types that answer this
379 query.
380 </p></div></div><div class="section" title="Examples"><div class="titlepage"><div><div><h3 class="title"><a id="pbds.using.examples"/>Examples</h3></div></div></div><p>
381 Additional code examples are provided in the source
382 distribution, as part of the regression and performance
383 testsuite.
384 </p><div class="section" title="Intermediate Use"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.examples.basic"/>Intermediate Use</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
385 Basic use of maps:
386 <code class="filename">basic_map.cc</code>
387 </p></li><li class="listitem"><p>
388 Basic use of sets:
389 <code class="filename">basic_set.cc</code>
390 </p></li><li class="listitem"><p>
391 Conditionally erasing values from an associative container object:
392 <code class="filename">erase_if.cc</code>
393 </p></li><li class="listitem"><p>
394 Basic use of multimaps:
395 <code class="filename">basic_multimap.cc</code>
396 </p></li><li class="listitem"><p>
397 Basic use of multisets:
398 <code class="filename">basic_multiset.cc</code>
399 </p></li><li class="listitem"><p>
400 Basic use of priority queues:
401 <code class="filename">basic_priority_queue.cc</code>
402 </p></li><li class="listitem"><p>
403 Splitting and joining priority queues:
404 <code class="filename">priority_queue_split_join.cc</code>
405 </p></li><li class="listitem"><p>
406 Conditionally erasing values from a priority queue:
407 <code class="filename">priority_queue_erase_if.cc</code>
408 </p></li></ul></div></div><div class="section" title="Querying with container_traits"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.examples.query"/>Querying with <code class="classname">container_traits</code> </h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
409 Using <code class="classname">container_traits</code> to query
410 about underlying data structure behavior:
411 <code class="filename">assoc_container_traits.cc</code>
412 </p></li><li class="listitem"><p>
413 A non-compiling example showing wrong use of finding keys in
414 hash-based containers: <code class="filename">hash_find_neg.cc</code>
415 </p></li><li class="listitem"><p>
416 Using <code class="classname">container_traits</code>
417 to query about underlying data structure behavior:
418 <code class="filename">priority_queue_container_traits.cc</code>
419 </p></li></ul></div></div><div class="section" title="By Container Method"><div class="titlepage"><div><div><h4 class="title"><a id="pbds.using.examples.container"/>By Container Method</h4></div></div></div><p/><div class="section" title="Hash-Based"><div class="titlepage"><div><div><h5 class="title"><a id="pbds.using.examples.container.hash"/>Hash-Based</h5></div></div></div><div class="section" title="size Related"><div class="titlepage"><div><div><h6 class="title"><a id="pbds.using.examples.container.hash.resize"/>size Related</h6></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
420 Setting the initial size of a hash-based container
421 object:
422 <code class="filename">hash_initial_size.cc</code>
423 </p></li><li class="listitem"><p>
424 A non-compiling example showing how not to resize a
425 hash-based container object:
426 <code class="filename">hash_resize_neg.cc</code>
427 </p></li><li class="listitem"><p>
428 Resizing the size of a hash-based container object:
429 <code class="filename">hash_resize.cc</code>
430 </p></li><li class="listitem"><p>
431 Showing an illegal resize of a hash-based container
432 object:
433 <code class="filename">hash_illegal_resize.cc</code>
434 </p></li><li class="listitem"><p>
435 Changing the load factors of a hash-based container
436 object: <code class="filename">hash_load_set_change.cc</code>
437 </p></li></ul></div></div><div class="section" title="Hashing Function Related"><div class="titlepage"><div><div><h6 class="title"><a id="pbds.using.examples.container.hash.hashor"/>Hashing Function Related</h6></div></div></div><p/><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
438 Using a modulo range-hashing function for the case of an
439 unknown skewed key distribution:
440 <code class="filename">hash_mod.cc</code>
441 </p></li><li class="listitem"><p>
442 Writing a range-hashing functor for the case of a known
443 skewed key distribution:
444 <code class="filename">shift_mask.cc</code>
445 </p></li><li class="listitem"><p>
446 Storing the hash value along with each key:
447 <code class="filename">store_hash.cc</code>
448 </p></li><li class="listitem"><p>
449 Writing a ranged-hash functor:
450 <code class="filename">ranged_hash.cc</code>
451 </p></li></ul></div></div></div><div class="section" title="Branch-Based"><div class="titlepage"><div><div><h5 class="title"><a id="pbds.using.examples.container.branch"/>Branch-Based</h5></div></div></div><div class="section" title="split or join Related"><div class="titlepage"><div><div><h6 class="title"><a id="pbds.using.examples.container.branch.split"/>split or join Related</h6></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
452 Joining two tree-based container objects:
453 <code class="filename">tree_join.cc</code>
454 </p></li><li class="listitem"><p>
455 Splitting a PATRICIA trie container object:
456 <code class="filename">trie_split.cc</code>
457 </p></li><li class="listitem"><p>
458 Order statistics while joining two tree-based container
459 objects:
460 <code class="filename">tree_order_statistics_join.cc</code>
461 </p></li></ul></div></div><div class="section" title="Node Invariants"><div class="titlepage"><div><div><h6 class="title"><a id="pbds.using.examples.container.branch.invariants"/>Node Invariants</h6></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
462 Using trees for order statistics:
463 <code class="filename">tree_order_statistics.cc</code>
464 </p></li><li class="listitem"><p>
465 Augmenting trees to support operations on line
466 intervals:
467 <code class="filename">tree_intervals.cc</code>
468 </p></li></ul></div></div><div class="section" title="trie"><div class="titlepage"><div><div><h6 class="title"><a id="pbds.using.examples.container.branch.trie"/>trie</h6></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
469 Using a PATRICIA trie for DNA strings:
470 <code class="filename">trie_dna.cc</code>
471 </p></li><li class="listitem"><p>
472 Using a PATRICIA
473 trie for finding all entries whose key matches a given prefix:
474 <code class="filename">trie_prefix_search.cc</code>
475 </p></li></ul></div></div></div><div class="section" title="Priority Queues"><div class="titlepage"><div><div><h5 class="title"><a id="pbds.using.examples.container.priority_queue"/>Priority Queues</h5></div></div></div><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>
476 Cross referencing an associative container and a priority
477 queue: <code class="filename">priority_queue_xref.cc</code>
478 </p></li><li class="listitem"><p>
479 Cross referencing a vector and a priority queue using a
480 very simple version of Dijkstra's shortest path
481 algorithm:
482 <code class="filename">priority_queue_dijkstra.cc</code>
483 </p></li></ul></div></div></div></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td align="left"><a accesskey="p" href="policy_data_structures.html">Prev</a> </td><td align="center"><a accesskey="u" href="policy_data_structures.html">Up</a></td><td align="right"> <a accesskey="n" href="policy_data_structures_design.html">Next</a></td></tr><tr><td align="left" valign="top">Chapter 22. Policy-Based Data Structures </td><td align="center"><a accesskey="h" href="../index.html">Home</a></td><td align="right" valign="top"> Design</td></tr></table></div></body></html>