题解

#include <iostream>
using namespace std;
int a[110];
int main() {
int n, x, ans = -1;
cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i];
cin >> x;
int l = 1, r = n;
while (l <= r) {
int mid = (l + r) / 2;
if (a[mid] >= x) {
r = mid - 1;
ans = mid;
} else {
l = mid + 1;
}
}
cout << ans;
return 0;
}