c语言统计程序执行时间

c语言程序执行时间

#include <iostream>
#include <cstdio>
#include <ctime>

int main() {
    std::clock_t start;
    double duration;

    start = std::clock();
    int i, sum;
    for(i=1; i<100000000; i++){
      sum+=i;
    }
    /* Your algorithm here */

    duration = ( std::clock() - start ) / (double) CLOCKS_PER_SEC;

    std::cout<<"printf: "<< duration <<'
';
}