Question: 
Write a python function to find the sum of xor of all pairs of numbers in the given array.


Model's Code:
def pair_OR_Sum(arr, n):
    total_xor_sum = 0
    for i in range(n):
        for j in range(i + 1, n):
            total_xor_sum += arr[i] ^ arr[j]
    return total_xor_sum



Sample Correct Code:
def pair_OR_Sum(arr,n) : 
    ans = 0 
    for i in range(0,n) :    
        for j in range(i + 1,n) :   
            ans = ans + (arr[i] ^ arr[j])          
    return ans 


Asserts:
assert pair_OR_Sum([5,9,7,6],4) == 47
assert pair_OR_Sum([7,3,5],3) == 12
assert pair_OR_Sum([7,3],2) == 4


Tests:
Test 1 of 3: PASS
Test 2 of 3: PASS
Test 3 of 3: PASS

Test 633 of 974: 472/633 (74.565560821485%): success