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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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<meta name="generator" content="HTML Tidy for Linux/x86 (vers 12 April 2005), see www.w3.org" />
<title>Priority Queue Random Int Push Pop Timing Test</title>
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</head>
<body>
<div id="page">
<h1>Priority Queue Random Integer <tt>push</tt> and
<tt>pop</tt> Timing Test</h1>
<h2><a name="description" id="description">Description</a></h2>
<p>This test inserts a number of values with i.i.d. integer
keys into a container using <tt>push</tt> , then removes them
using <tt>pop</tt> . It measures the average time for
<tt>push</tt> and <tt>pop</tt> as a function of the number of
values.</p>
<p>(The test was executed with <a href="http://gcc.gnu.org/viewcvs/*checkout*/trunk/libstdc%2B%2B-v3/testsuite/performance/ext/pb_ds/priority_queue_random_int_push_pop_timing.cc">
<tt>priority_queue_random_int_push_pop_timing_test</tt></a>
thirty_years_among_the_dead_preproc.txt 200 200 2100)</p>
<h2><a name="purpose" id="purpose">Purpose</a></h2>
<p>The test checks the effect of different underlying
data structures (see <a href="pq_design.html#pq_imp">Design::Priority
Queues::Implementations</a>).</p>
<h2><a name="results" id="results">Results</a></h2>
<p>Figures <a href="#NPG">NPG</a>, <a href="#NPM">NPM</a>, and
<a href="#NPL">NPL</a> shows the results for the native
priority queues and <tt>pb_ds</tt> 's priority queues in
<a href="pq_performance_tests.html#gcc"><u>g++</u></a>,
<a href="pq_performance_tests.html#msvc"><u>msvc++</u></a>, and
<a href="pq_performance_tests.html#local"><u>local</u></a>,
respectively.</p>
<div id="NPG_res_div">
<div id="NPG_gcc">
<div id="NPG_priority_queue_random_int_push_pop_timing_test">
<div id="NPG_pq">
<div id="NPG_Native_and__tt_pb_ds_455tt__priority_queue__tt_push_455tt___tt_pop_455tt__timing_test"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPG" id="NPG"><img src="priority_queue_random_int_push_pop_timing_test_gcc.png" alt="no image" /></a></h6>NPG: Native and <tt>pb ds</tt> priority queue <tt>push</tt> <tt>pop</tt> timing test - <a href="pq_performance_tests.html#gcc">g++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
thin_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
</li>
<li>
rc_binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
</li>
<li>
binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
</li>
<li>
pairing_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
</li>
<li>
n_pq_deque-
<tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
<li>
n_pq_vector-
<tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
<li>
binary_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
</li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NPM_res_div">
<div id="NPM_msvc">
<div id="NPM_priority_queue_random_int_push_pop_timing_test">
<div id="NPM_pq">
<div id="NPM_Native_and__tt_pb_ds_455tt__priority_queue__tt_push_455tt___tt_pop_455tt__timing_test"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPM" id="NPM"><img src="priority_queue_random_int_push_pop_timing_test_msvc.png" alt="no image" /></a></h6>NPM: Native and <tt>pb ds</tt> priority queue <tt>push</tt> <tt>pop</tt> timing test - <a href="pq_performance_tests.html#msvc">msvc++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
thin_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
</li>
<li>
rc_binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
</li>
<li>
binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
</li>
<li>
pairing_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
</li>
<li>
n_pq_deque-
<tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
<li>
n_pq_vector-
<tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
<li>
binary_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
</li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NPL_res_div">
<div id="NPL_local">
<div id="NPL_priority_queue_random_int_push_pop_timing_test">
<div id="NPL_pq">
<div id="NPL_Native_and__tt_pb_ds_455tt__priority_queue__tt_push_455tt___tt_pop_455tt__timing_test"><div style = "border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPL" id= "NPL"><img src="priority_queue_random_int_push_pop_timing_test_local.png" alt="no image" /></a></h6>NPL: Native and <tt>pb ds</tt> priority queue <tt>push</tt> <tt>pop</tt> timing test - <a href = "pq_performance_tests.html#local">local</a></div><div style = "width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<h2><a name="observations" id="observations">Observations</a></h2>
<p>Binary heaps are the most suited for sequences of
<tt>push</tt> and <tt>pop</tt> operations of primitive types
(<i>e.g.</i> <tt><b>int</b></tt>s). This is explained in
<a href="priority_queue_random_int_push_timing_test.html">Priority
Queue Random Int <tt>push</tt> Timing Test</a> . (See <a href="priority_queue_text_push_pop_timing_test.html">Priority Queue
Text <tt>push</tt> Timing Test</a> for the case of primitive
types.)</p>
<p>At first glance it seems that the STL's vector-based
priority queue is approximately on par with <tt>pb_ds</tt>'s
corresponding priority queue. There are two differences
however:</p>
<ol>
<li>The STL's priority queue does not downsize the underlying
vector (or deque) as the priority queue becomes smaller
(see <a href="priority_queue_text_pop_mem_usage_test.html">Priority Queue
Text <tt>pop</tt> Memory Use Test</a>). It is therefore
gaining some speed at the expense of space.</li>
<li>From <a href="priority_queue_random_int_push_pop_timing_test.html">Priority
Queue Random Integer <tt>push</tt> and <tt>pop</tt> Timing
Test</a>, it seems that the STL's priority queue is slower in
terms of <tt>pus</tt> operations. Since the number of
<tt>pop</tt> operations is at most that of <tt>push</tt>
operations, the test here is the "best" for the STL's
priority queue.</li>
</ol>
<p><a href="pq_performance_tests.html#pq_observations">Priority-Queue
Performance Tests::Observations</a> discusses this further and
summarizes.</p>
</div>
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