题解

#include<iostream>
#include<cmath>
using namespace std;
int main(){
    int n,m,high=0;
    cin>>n>>m;
    int a[n+10];
    for(int i=0;i<n;i++){
        cin>>a[i];
        high=max(a[i],high);
    }
    int l=0,r=high,ans=0;
    while(l<=r){
        int mid=(l+r)/2;
        long long sum=0;
        for(int i=0;i<n;i++){
            if(a[i]>mid){
                sum+=a[i]-mid;
            }
        }
        if(sum>=m){
            ans=mid;l=mid+1;
        }else{
            r=mid-1;
        }
    }
    cout<<ans;
    return 0;
}