C++几处代码优化记录

 //以下基于Debug调试模式，

map<int, string> mss;
clock_t c1, c2;
c1 = clock();
for (int i=0; i<500000; i++)
{
unsigned int lun = 123324;
char num[] ="012345678912";
vector<char> vv;

//【1】ostringstream 效率低于_itoa_s

//ostringstream lstrStream;
//lstrStream<<lun;                            //耗时6.875秒

//char cc[12];
//_itoa_s(lun, cc, 12, 10);                   //耗时0.063秒

//【2】map[索引]=值 效率低于 map.insert

//mss[i] = "abdfadaf";                        //耗时9.172秒
//mss.insert(make_pair(i, "abdfadaf"));       //耗时7.454秒

//【3】vector单个push_back 效率低于 vector.insert
//for (int n=0; n<12; n++)                    //耗时30.344秒
//{
//    vv.push_back(num
);
//}
//vv.insert(vv.end(), &num[0], &num[0]+12);    //耗时3.079秒
}
c2 = clock();
double d = (double)(c2-c1)/CLOCKS_PER_SEC;