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7<title>Priority Queue Random Int Push Pop Timing Test</title>
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12<h1>Priority Queue Random Integer <tt>push</tt> and
13    <tt>pop</tt> Timing Test</h1>
14<h2><a name="description" id="description">Description</a></h2>
15<p>This test inserts a number of values with i.i.d. integer
16    keys into a container using <tt>push</tt> , then removes them
17    using <tt>pop</tt> . It measures the average time for
18    <tt>push</tt> and <tt>pop</tt> as a function of the number of
19    values.</p>
20<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">
21<tt>priority_queue_random_int_push_pop_timing_test</tt></a>
22    thirty_years_among_the_dead_preproc.txt 200 200 2100)</p>
23<h2><a name="purpose" id="purpose">Purpose</a></h2>
24<p>The test checks the effect of different underlying
25    data structures (see <a href="pq_design.html#pq_imp">Design::Priority
26    Queues::Implementations</a>).</p>
27<h2><a name="results" id="results">Results</a></h2>
28<p>Figures <a href="#NPG">NPG</a>, <a href="#NPM">NPM</a>, and
29    <a href="#NPL">NPL</a> shows the results for the native
30    priority queues and <tt>pb_ds</tt> 's priority queues in
31    <a href="pq_performance_tests.html#gcc"><u>g++</u></a>,
32    <a href="pq_performance_tests.html#msvc"><u>msvc++</u></a>, and
33    <a href="pq_performance_tests.html#local"><u>local</u></a>,
34    respectively.</p>
35<div id="NPG_res_div">
36<div id="NPG_gcc">
37<div id="NPG_priority_queue_random_int_push_pop_timing_test">
38<div id="NPG_pq">
39<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>
40<ol>
41<li>
42thin_heap-
43<a href="priority_queue.html"><tt>priority_queue</tt></a>
44 with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
45</li>
46<li>
47rc_binomial_heap-
48<a href="priority_queue.html"><tt>priority_queue</tt></a>
49 with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
50</li>
51<li>
52binomial_heap-
53<a href="priority_queue.html"><tt>priority_queue</tt></a>
54 with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
55</li>
56<li>
57pairing_heap-
58<a href="priority_queue.html"><tt>priority_queue</tt></a>
59 with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
60</li>
61<li>
62n_pq_deque-
63<tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
64<li>
65n_pq_vector-
66<tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
67<li>
68binary_heap-
69<a href="priority_queue.html"><tt>priority_queue</tt></a>
70 with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
71</li>
72</ol>
73</div><div style="width: 100%; height: 20px"></div></div>
74</div>
75</div>
76</div>
77</div>
78<div id="NPM_res_div">
79<div id="NPM_msvc">
80<div id="NPM_priority_queue_random_int_push_pop_timing_test">
81<div id="NPM_pq">
82<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>
83<ol>
84<li>
85thin_heap-
86<a href="priority_queue.html"><tt>priority_queue</tt></a>
87 with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
88</li>
89<li>
90rc_binomial_heap-
91<a href="priority_queue.html"><tt>priority_queue</tt></a>
92 with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
93</li>
94<li>
95binomial_heap-
96<a href="priority_queue.html"><tt>priority_queue</tt></a>
97 with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
98</li>
99<li>
100pairing_heap-
101<a href="priority_queue.html"><tt>priority_queue</tt></a>
102 with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
103</li>
104<li>
105n_pq_deque-
106<tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
107<li>
108n_pq_vector-
109<tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
110<li>
111binary_heap-
112<a href="priority_queue.html"><tt>priority_queue</tt></a>
113 with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
114</li>
115</ol>
116</div><div style="width: 100%; height: 20px"></div></div>
117</div>
118</div>
119</div>
120</div>
121<div id="NPL_res_div">
122<div id="NPL_local">
123<div id="NPL_priority_queue_random_int_push_pop_timing_test">
124<div id="NPL_pq">
125<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>
126</div>
127</div>
128</div>
129</div>
130<h2><a name="observations" id="observations">Observations</a></h2>
131<p>Binary heaps are the most suited for sequences of
132    <tt>push</tt> and <tt>pop</tt> operations of primitive types
133    (<i>e.g.</i> <tt><b>int</b></tt>s). This is explained in
134    <a href="priority_queue_random_int_push_timing_test.html">Priority
135    Queue Random Int <tt>push</tt> Timing Test</a> . (See <a href="priority_queue_text_push_pop_timing_test.html">Priority Queue
136    Text <tt>push</tt> Timing Test</a> for the case of primitive
137    types.)</p>
138<p>At first glance it seems that the STL's vector-based
139    priority queue is approximately on par with <tt>pb_ds</tt>'s
140    corresponding priority queue. There are two differences
141    however:</p>
142<ol>
143<li>The STL's priority queue does not downsize the underlying
144      vector (or deque) as the priority queue becomes smaller
145      (see <a href="priority_queue_text_pop_mem_usage_test.html">Priority Queue
146      Text <tt>pop</tt> Memory Use Test</a>). It is therefore
147      gaining some speed at the expense of space.</li>
148<li>From <a href="priority_queue_random_int_push_pop_timing_test.html">Priority
149      Queue Random Integer <tt>push</tt> and <tt>pop</tt> Timing
150      Test</a>, it seems that the STL's priority queue is slower in
151      terms of <tt>pus</tt> operations. Since the number of
152      <tt>pop</tt> operations is at most that of <tt>push</tt>
153      operations, the test here is the "best" for the STL's
154      priority queue.</li>
155</ol>
156<p><a href="pq_performance_tests.html#pq_observations">Priority-Queue
157    Performance Tests::Observations</a> discusses this further and
158    summarizes.</p>
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