3、9、10样例没过

#include<bits/stdc++.h>
using namespace std;
int tree[1000010];
long long N,M;
bool judge(int h){
	int sum=0; //总共能得到多少木材
	for(int i=1;i<=N;i++){
		if(tree[i]>h){
			sum+=(tree[i]-h);
		}
	} 
	if(sum>=M){
		return true;
	}else{
		return false;
	}
	 
} 
int main(){
	
	cin>>N>>M;
	int max=0;
	for(int i=1;i<=N;i++){
		cin>>tree[i];
		if(tree[i]>max){
			max=tree[i];
		}
	}
	
	long long low=1,high=max;
	while(low<high){
		int mid=(low+high+1)/2;
		if(judge(mid)){
			low=mid;
		}else{
			high=mid-1;
		}
	}
	cout<<low;
	return 0;
}