阅读程序写结果：

#include <iostream>

using namespace std;

int main() {

const int SIZE = 100;

int n, f, i, left, right, middle, a[SIZE];

cin>>n>>f;

for (i = 1; i <= n; i++)

cin>>a[i];

left = 1;

right = n;

do {

middle = (left + right) / 2;

if (f <= a[middle])

right = middle;

else

left = middle + 1;

} while (left < right);

cout<<left<<endl;

return 0;

}

输入：

12 17

2 4 6 9 11 15 17 18 19 20 21 25