Sum of bit differences

PROBLEM :

Write a program to find the sum of bit differences in all pairs that can be formed from array elements n. Bit difference of a pair (x, y) is a count of different bits at same positions in binary representations of x and y. For example, bit difference for 2 and 7 is 2. Binary representation of 2 is 010 and 7 is 111 ( first and last bits differ in two numbers).

Input: The first line of input contains an integer T denoting the number of test cases. First line of the test case will contain an array of elements n.
Output: The sum of bit differences of all pairs that can be formed by given array.

Constraints:
1 <=T<= 100
1 <=N<= 10
1 <=a[i]<= 10

Example:
Input:
2
2
1 2
3
1 3 5

Output:
4
8

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SIMPLE c++ IMPLEMENTATION :
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#include<iostream>
using namespace std;
int main()
{
    int t ;
    cin>>t ;
    while(t--){
        int no ;
        cin>>no ;
       
        int arr[no] ;
        for(int i=0;i<no;i++)
            cin>>arr[i] ;
       
        int ans=0 ;
        for(int i=0;i<32;i++){
            int count=0 ;
            for(int j=0;j<no;j++){
                if(arr[j]&(1<<i))
                    count++ ;
            }
            ans+=count*(no-count) ;
        }
        cout<<ans*2<<endl  ;
    }
return 0;
}

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