计算程序运行的时间一个函数

 1 #include<iostream>
 2 #include<time.h>
 3 using namespace std;
 4 int main()
 5 {
 6     double n;
 7     while (cin >> n)
 8     {
 9         int k = 0;
10         for (int i = 0; i < n; i++)
11         {
12             k++;
13         }
14         cout << k << endl;
15         cout << "time is" << double(clock()) / CLOCKS_PER_SEC<<endl;
16     }
17     return 0;
18 }