我尝试了一些C ++基准测试，但我很惊讶-线性搜索似乎占据了几十个项目，而且还没有找到二进制搜索更适合那些大小的情况。也许gcc的STL调整不当？但是然后-
您将用什么来实现这两种搜索？-）这是我的代码，因此每个人都可以看到我是否做过一些愚蠢的事情，这些事情会严重扭曲计时……
#include <vector>#include <algorithm>#include <iostream>#include <stdlib.h>int data[] = {98, 50, 54, 43, 39, 91, 17, 85, 42, 84, 23, 7, 70, 72, 74, 65, 66, 47, 20, 27, 61, 62, 22, 75, 24, 6, 2, 68, 45, 77, 82, 29, 59, 97, 95, 94, 40, 80, 86, 9, 78, 69, 15, 51, 14, 36, 76, 18, 48, 73, 79, 25, 11, 38, 71, 1, 57, 3, 26, 37, 19, 67, 35, 87, 60, 34, 5, 88, 52, 96, 31, 30, 81, 4, 92, 21, 33, 44, 63, 83, 56, 0, 12, 8, 93, 49, 41, 58, 89, 10, 28, 55, 46, 13, 64, 53, 32, 16, 90 };int tosearch[] = {53, 5, 40, 71, 37, 14, 52, 28, 25, 11, 23, 13, 70, 81, 77, 10, 17, 26, 56, 15, 94, 42, 18, 39, 50, 78, 93, 19, 87, 43, 63, 67, 79, 4, 64, 6, 38, 45, 91, 86, 20, 30, 58, 68, 33, 12, 97, 95, 9, 89, 32, 72, 74, 1, 2, 34, 62, 57, 29, 21, 49, 69, 0, 31, 3, 27, 60, 59, 24, 41, 80, 7, 51, 8, 47, 54, 90, 36, 76, 22, 44, 84, 48, 73, 65, 96, 83, 66, 61, 16, 88, 92, 98, 85, 75, 82, 55, 35, 46 };bool binsearch(int i, std::vector<int>::const_iterator begin,std::vector<int>::const_iterator end) { return std::binary_search(begin, end, i);}bool linsearch(int i, std::vector<int>::const_iterator begin,std::vector<int>::const_iterator end) { return std::find(begin, end, i) != end;}int main(int argc, char *argv[]){ int n = 6; if (argc < 2) { std::cerr << "need at least 1 arg (l or b!)" << std::endl; return 1; } char algo = argv[1][0]; if (algo != 'b' && algo != 'l') { std::cerr << "algo must be l or b, not '" << algo << "'" << std::endl; return 1; } if (argc > 2) { n = atoi(argv[2]); } std::vector<int> vv; for (int i=0; i<n; ++i) { if(data[i]==-1) break; vv.push_back(data[i]); } if (algo=='b') { std::sort(vv.begin(), vv.end()); } bool (*search)(int i, std::vector<int>::const_iterator begin, std::vector<int>::const_iterator end); if (algo=='b') search = binsearch; else search = linsearch; int nf = 0; int ns = 0; for(int k=0; k<10000; ++k) { for (int j=0; tosearch[j] >= 0; ++j) { ++ns; if (search(tosearch[j], vv.begin(), vv.end())) ++nf; } } std::cout << nf <<'/'<< ns << std::endl; return 0;}和我在核心二人组上的一些时间安排：
AmAir:stko aleax$ time ./a.out b 931910000/2030000real 0m0.230suser 0m0.224ssys 0m0.005sAmAir:stko aleax$ time ./a.out l 931910000/2030000real 0m0.169suser 0m0.164ssys 0m0.005s
无论如何，它们都是可重复的……
OP说：Alex，我编辑了程序，只用1..n填充了数组，而不运行std :: sort，并进行了大约一千万次（模整数除法）搜索。在奔腾4上，n =
150处的二进制搜索开始远离线性搜索。很抱歉图表颜色。
二进制搜索与线性搜索http://spreadsheets.google.com/pub?key=tzWXX9Qmmu3_COpTYkTqsOA&oid=1&output=image
