Help me in solving PAIREQ problem.....what wrong in this

help
,
1

My issue

My code

#include <iostream>
#include<algorithm>
using namespace std;

int main() {
	// your code goes here
	int t,n;
	cin>>t;
	while(t--){
	    cin>>n;
	    int a[n];
	    for(int i=0;i<n;i++){
	        cin>>a[i];
	    }
// 	   sort(a,a+n);
      
    //   if(a[0]==a[n-1]){
    //       cout<<"0"<<endl;
    //   }
      int mid=(n)/2;
      int sum=0,count=0;
      for(int i=0;i<n;i++){
          if(a[mid]>=a[i]){
              count=a[mid]-a[i];
              sum+=count;
          }
          else {
              count=a[i]-a[mid];
               sum+=count;
          }
      }
      cout<<sum<<endl;
      
	}
	return 0;
}

Problem Link: CodeChef: Practical coding for everyone