全 Wa ，大佬求助

#include <iostream>
#include <cstring>
using namespace std;
const int MAXX = 1e6 + 11;
int n,m;
int L,R,Mid;
int a[MAXX];
int check(int x) {
	int sum = 0;
	for (int i = 1; i <= n; i ++) {
		if (a[i] > x) {
			sum += x - a[i];
		}
	}
	return sum;
}
int main() {
	cin >> n >> m;
	for (int i = 1; i <= n; i ++) {
		cin >> a[i];
		R = max(R,a[i]);
	}
	while (L <= R) {
		Mid = L + R >> 1;
		if (check(Mid) >= m) {
			L = Mid + 1;
		} else {
			R = Mid - 1;
		}
	}
	cout << L;
	return 0;
}