Help me in solving N3AL_ problem

help
,
1

My issue

I think my code is working fine in all Testcases but still after 20+ submissions my solution is getting wrong answer on a hidden testcase.

My code

#include <bits/stdc++.h>
using namespace std;
using ll=long long;

int main() {

	int t;
	cin>>t;
	while(t--){
	    int n;
	    cin>>n;
	    vector<int> arr(n);
	    for(int i=0;i<n;i++){
	        cin>>arr[i];
	    }
        
	    sort(arr.begin(), arr.end());

        vector<int> prefix(n);
        prefix[0]=arr[0];
        for(int i=1;i<n;i++){
            prefix[i]=prefix[i-1]+arr[i];
        }
     
        int ans=0;
        for(int i=0;i<n;i++){
            
            int curr=(i+1)*(i+1)+prefix[n-1]-prefix[i];
            
            ans=max(ans,curr);
        }
        
        int final=max(ans,prefix[n-1]);
        cout<<final<<endl;

        
	    
	}

}

Problem Link: qUiRkY qUesTs (Easy) Practice Coding Problem