c++如何计算程序运行的时间

方案一：

#include<iostream>
#include<ctime>
using namespace std;
 
int main()
{
    clock_t start,finish;
    start=clock();
     
    cout << "HW .... " << endl;
 
    finish=clock();
 
    cout << finish-start   << "/" << CLOCKS_PER_SEC  << " (s) "<< endl;
     
    return 0;
}

方案二：

clock_t st = clock();

.......

......

printf("time: %.0lfms\n", (clock()-st)*1000.0 / CLOCKS_PER_SEC);

方案三：

c语言计算函数消耗时间:

#include <sys/time.h>

#include <unistd.h>

struct timeval tv1, tv2;

double sec =0;

gettimeofday(&tv1, 0);

HEGGTOPCOLLECTOR hTopCollector = eggTopCollector_new(0); // top
10

gettimeofday(&tv2, 0);

sec = (double)(tv2.tv_sec - tv1.tv_sec) + (double)(tv2.tv_usec - tv1.tv_usec) /1000000;

printf("time1: %f\n",
sec);