Help me in solving MAKEALLEQUAL problem

help
,
1

My issue

#include<bits/stdc++.h>
using namespace std;
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int t; cin>>t;
	while(t--){
		long long n,m; cin>>n>>m;
		long long dp[n];
		for(int i=0; i<n; i++){
			cin>>dp[i];
		}
		sort(dp,dp+n);
		long long ans=0;
		int x=1;
		for(int i=0; i+1<n; i++){
			ans+=dp[n-1]-dp[i];
		}
		cout<<max((dp[n-1]-dp[0]),(ans%m==0)? ans/m: (ans/m)+1)<<"\n";
	}
	return 0;
}

Why we take the diff between max and min?

5 2
1 2 3 4 5

Iteration 1(index 3,4): 1 2 4 5 5
Iteration 2(index 2,3): 1 3 5 5 5
Iteration 3(index 1,2): 2 4 5 5 5
Iteration 4(index 1,2): 3 5 5 5 5
Iteration 5(index 1,2): 4 5 5 5 5
Iteration 6(index 1,2): 5 5 5 5 5

Here it needs 6 iterations but the following code gives 5 which is accepted. Why?

Problem Link: Make All Equal Practice Coding Problem - CodeChef

2

@shahnur00
for
5 2
1 2 3 4 5
it will go like this
1st select (1,3) → 2 2 4 4 5
2nd select (3,4) → 2 2 5 5 5
3rd select (1,2) → 3 3 5 5 5
4th select (1,2) → 4 4 5 5 5
5th select (1,2) → 5 5 5 5 5
so the answer would be 5.