c++ map 字符串键值和数值键值查找效率测试

结论：数值类型键值比字符串快了9倍。

代码：

#include <iostream>
#include <functional>
#include <thread>
#include <array>
#include <unordered_map>
#include <map>
#include <assert.h>
#include <string>

using namespace std;

map<std::string, int> map1;
map<int, int> map2;


int main(void)
{
    int num = 10000;

    int loop = 100000;

    for (int i = 0; i < num; ++i)
    {
        map1[to_string(i + 100000)] = i;
        map2[i + 100000] = i;
    }

    int begin = clock();
    for (int i = 0; i < loop; ++i)
    {
        map1["123123"];
    }

    cout << clock() - begin << endl;
    begin = clock();
    for (int i = 0; i < loop; ++i)
    {
        map2[123];
    }

    cout << clock() - begin << endl;
    begin = clock();
    for (int i = 0; i < loop; ++i)
    {
    }

    cout << clock() - begin << endl;
    begin = clock();
    return 0;
}

输出结果：

937
101
0