stdvector与stdlist的执行速度比较(C-C)(STL).doc

std:vector与std:list的执行速度比较 (C/C+) (STL) std:vector与std:list的执行速度比较 (C/C+) (STL) 收藏 STL中的container各有专长，最常用的是std:vector，可以完全取代array，第二常用的是std:list。std:vector的优点在于non-sequential access超快，新增数据于数据后端超快，但insert和erase任意资料则相当缓慢；std:list则是insert和erase速度超快，但non-sequential access超慢，此范例以实际时间比较vector和list间的优缺点。 1/*/* 2(C) OOMusou 2006 3 4Filename : VectorVsList.cpp 5Compiler : Visual C+ 8.0 6Description : Demo the performance difference between std:vector and std:list 7*/ 8#include 9 #include 10#include 11 #include 12 13 / Add to Vector at end 14void addToVectorAtEnd(); 15/ Add to List at end 16void addToListAtEnd(); 17/ Calculate time for adding to end 18void addToEnd(); 19 20/ Add to Vector anywhere 21void addToVectorAnywhere(); 22/ Add to List anywhere 23void addToListAnywhere(); 24/ Calculate time for adding anywhere 25void addAnywhere(); 26 27/ Remove from Vector anywhere 28void removeFromVectorAnywhere(); 29/ Remove from List anywhere 30void removeFromListAnywhere(); 31/ Calculate time for removing anywhere 32void removeAnywhere(); 33 34/ Non-sequential access to Vector 35void nonSequentialAccessToVector(); 36/ Non-sequential access to List 37void nonSequentialAccessToList(); 38/ Caculate time for non-sequential access to 39void nonSequentialAccess(); 40 41std:vector vector1; 42std:list list1; 43 44int main() 45 / Calculate time for adding to end 46 addToEnd(); 47 48 / Calculate time for adding anywhere 49 addAnywhere(); 50 51 / Calculate time for removing anywhere 52 removeAnywhere(); 53 54 / Caculate time for non-sequential access to 55 nonSequentialAccess(); 56 57 58/ Add to Vector at end 59void addToVectorAtEnd() 60 for(int i=0; i != 1000000; +i) 61 vector1.push_back(i); 62 63 64 65/ Add to List at end 66void addToListAtEnd() 67 for(int i=0; i != 1000000; +i) 68 list1.push_back(i); 69 70 71 72/ Calculate time for adding to end 73void addToEnd() 74 clock_t addToVectorAtEndClock = clock(); 75 addToVectorAtEnd(); 76 addToVectorAtEndClock = clock() - addToVectorAtEndClock; 77 78 std:cout Vector Insertion at the end Process time: (double)addToVectorAtEndClock/CLOCKS_PER_SEC sec std:endl; 79 80 clock_t addToListAtEndClock = clock(); 81 addToListAtEnd(); 82 addToListAtEndClock = clock() - addToListAtEndClock; 83 84 std:cout List Insertion at the end Process time: (double)addToListAtEndClock/CLOCKS_PER_SEC sec std:endl; 85 86 if (addToVectorAtEndClock addToListAtEndClock) 87 std:cout Insertion at the end : Vector wins std:endl; 88 89 else 90 std:cout Insertion at the end : List wins std:endl; 91 92 93 94/ Add to Vector anywhere 95void addToVectorAnywhere() 96 / Add to 50000th 97 std:vector:iterator iter = vector1.begin(); 98 99 for(int i = 0; i = 500; +i) 100 +iter;101 iter = vector1.insert(iter,i);102 103104105/ Add to List anywhere106void addToListAnywhere() 107 / Add to 50000th108 std:list:iterator iter = list1.begin();109110 for(int i = 0; i != 500; +i) 111 +iter;112 iter = list1.insert(iter,i);113 114115116/ Calculate time for adding anywhere117void addAnywhere() 118 clock_t addToVectorAnywhereClock = clock();119 addToVectorAnywhere();120 addToVectorAnywhereClock = clock() - addToVectorAnywhereClock;121122 std:cout Vector Insertion anywhere Process time: (double)addToVectorAnywhereClock/CLOCKS_PER_SEC sec std:endl;123124 clock_t addToListAnywhereClock = clock();125 addToListAnywhere();126 addToListAnywhereClock = clock() - addToListAnywhereClock;127128 std:cout List Insertion anywhere Process time: (double)addToListAnywhereClock/CLOCKS_PER_SEC sec std:endl;129130 if (addToVectorAnywhereClock addToListAnywhereClock) 131 std:cout Insertion anywhere : Vector wins std:endl;132 133 else 134 std:cout Insertion anywhere : List wins std:endl;135 136137138/ Remove from Vector anywhere139 void removeFromVectorAnywhere() 140 std:vector:iterator iter = vector1.begin();141142 for(int i = 0; i != 500; +i) 143 +iter;144 iter = vector1.erase(iter);145 146147148/ Remove from List anywhere149void removeFromListAnywhere() 150 std:list:iterator iter = list1.begin();151152 for(int i = 0; i != 500; +i) 153 +iter;154 iter = list1.erase(iter);155 156157158/ Calculate time for removing anywhere159 void removeAnywhere() 160 clock_t removeFromVectorAnywhereClock = clock();161 removeFromVectorAnywhere();162 removeFromVectorAnywhereClock = clock() - removeFromVectorAnywhereClock;163164 std:cout Vector deletion anywhere Process time: (double)removeFromVectorAnywhereClock/CLOCKS_PER_SEC sec std:endl;165166 clock_t removeFromListAnywhereClock = clock();167 removeFromListAnywhere();168 removeFromListAnywhereClock = clock() - removeFromListAnywhereClock;169170 std:cout List deletion anywhere Process time: (double)removeFromListAnywhereClock/CLOCKS_PER_SEC sec std:endl;171172 if (removeFromVectorAnywhereClock removeFromListAnywhereClock) 173 std:cout Deletion anywhere : Vector wins std:endl;174 175 else 176 std:cout Deletion anywhere : List wins std:endl;177 178179180/ Non-sequential access to Vector181void nonSequentialAccessToVector() 182 for(int i = 0; i != 10000; +i) 183 int m = vector1.at(i);184 185186187/ Non-sequential access to List188void nonSequentialAccessToList() 189 for(int i = 0; i != 10000; +i) 190 std:list:const_iterator iter = list1.begin();191 for(int k = 0; k = i; +k) 192 +iter;193 194195 int m = (*iter);196 197198199/ Caculate time for non-sequential access to 200void nonSequentialAccess() 201 clock_t nonSequentialAccessToVectorClock = clock();202 nonSequentialAccessToVector();203 nonSequentialAccessToVectorClock = clock() - nonSequentialAccessToVectorClock;204205 std:cout Vector non-sequential access Process time: (double)nonSequentialAccessToVectorClock/CLOCKS_PER_SEC sec std:endl;206207 clock_t nonSequentialAccessToListClock = clock();208 nonSequentialAccessToList();209 nonSequentialAccessToListClock = clock() - nonSequentialAccessToListClock;210211 std:cout List non-sequential access Process time: (double)nonSequentialAccessToListClock/CLOCKS_PER_SEC sec std:endl;212213 if (nonSequentialAccessToVectorClock nonSequentialAccessToListClock) 214 std:cout Non-sequential : Vector wins std:endl;215 216 else 217 std:cout Non-sequential : List wins std:endl;218 219执行结果(Debug mode) 1Vector Insertion at the end Process time:3.094 sec 2List Insertion at the end Process time:10.205 sec 3Insertion at the end : Vector wins 4Vector Insertion anywhere Process time:5.548 sec 5List Insertion anywhere Process time:0.01 sec 6Insertion anywhere : List wins 7Vector deletion anywhere Process time:4.756 sec 8List deletion anywhere Process time:0.011 sec 9Deletion anywhere : List wins10Vector non-sequential access Process time:0.11 sec11List non-sequential access Process time:21.12 sec12Non-sequential : Vector wins(Release Mode) 1Vector Insertion at the end Process time:0.06 sec 2List Insertion at the end Process time:0.39 sec 3Insertion at the end : Vector wins 4Vector Insertion anywhere Process time:4.757 sec 5List Insertion anywhere Process time:0 sec 6Insertion anywhere : List wins 7Vector deletion anywhere Process time:4.717 sec 8List deletion anywhere Process time:0 sec 9Deletion anywhere : List wins10Vector non-sequential access Process time:0 sec11List non-sequential access Process time:0.491 sec12Non-sequential : Vector wins可见经过compiler优化后，速度差异非常明显本文来自CSDN博客，转载请标明出处：/ljx0305/archive/2009/09/05/4523408.aspxC+ error C2440: “类型转换” : 无法从“std:vector:iterator”转换为“PPkgHead”圆环套圆环之迭代器话说这一日是风平浪静，万里乌云，俺的心情好的没得说，收到命令清理A区（写部分代码，其中有在VC6下己完成的代码要移植到VC7下），一路上很轻松，用饭得标的话来说就是卡卡地！在快完成时出现错误。error C2440: “类型转换” : 无法从“std:vector:iterator”转换为“PPkgHead” with _Ty=BYTE 出错代码PPkgHead pHead = (PPkgHead )m_vPkgRecv.begin();晕之，在VC6下可以编译通过的呀！看看为啥不让转换呢？看了一下返回值是std:vector:iterator 或是 std:vector:const_iterator , 在begin()后面加了一个点看到了iterator有下面还有一个iterator（果然是圆环套圆环）和加、减、等运算符操作，很是郁闷应该怎么转换呢？到vector里看了一下原来是一个类 class iterator 在里面看到了几个函数 const_reference operator*() const / return designated object return