二分模板

#include<bits/stdc++.h>
using namespace std;
int num[10086];
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> num[i];
	}
	int x;
	cin >> x;
	//sort(num, num + 1);
	int l = 0, r = n - 1;
	while (l <= r) {
		int mid = (l + r) / 2;
		if (num[mid] == x) {
			cout << "Yes" << endl;
			return 0;
		} else if (num[mid] < x) {
			l = mid + 1;
		} else if (num[mid] > x) {
			r = mid - 1;
		}
	}
	cout << "-1" << endl;
	return 0;
}