Add a timer function in c ++ program

#include "stdio.h"
#include "time.h"

int main()
{
    clock_t start,finish;
    start=clock();
    ......
    ......
    ......
    finish=clock();
    //printf("共耗时%.3lf秒",((double)finish-start)/1000);
    printf("%d/n%f/n", res, (double)(finish - start) / CLOCKS_PER_SEC);
    return 0;
}