You are given an array of n integer numbers a1, a2, . . . , an. Calculate the number of pair of indices (i, j) such that 1 ≤ i < j ≤ n and ai xor aj = 0.

Question:

You are given an array of n integer numbers a1, a2, . . . , an. Calculate the number of pair of indices (i, j) such that 1 ≤ i < j ≤ n and ai xor aj = 0. 

 

Input format 

 

- First line: n denoting the number of array elements

 - Second line: n space-separated integers a1, a2, . . . , an. 

 

Output format 

 

Output the required number of pairs. 

 

Constraints 

 

1 ≤ n ≤ 106 1 ≤ ai ≤ 109 

 

SAMPLE INPUT  

 

5 

1 3 1 4 3 

 

SAMPLE OUTPUT  

 

2 

 

Explanation 

 

The 2 pair of indices are (1, 3) and (2,5). 

ANSWER:

#include <stdio.h>

int main()

{

    int n, arr[1000000], i, j, count; 

    scanf("%d", &n); 

    for (i = 0; i < n; i++) 

    {

     scanf("%d", &arr[i]);

    }

    count = 0; 

    for (i = 0; i < n - 1; i++) 

    { 

      for (j = i + 1; j < n; j++) 

      { 

       if (arr[i] == arr[j]) 

        {

          count++; 

        }

      } 

     } 

 printf("%d", count); 

    return 0;

}

OUTPUT:

5                                                                                                          

1 3 1 4 3                                                                                                  

2