Creating sumBitDifferences Function

static int sumBitDifferences(int[] arr, int n)
{
    int ans = 0;  // Initialize result

    return ans;
}

Now we want looping thorugh all the bits.

static int sumBitDifferences(int[] arr, int n)
{
    int ans = 0;  // Initialize result

    // traverse over all bits
    for (int i = 0; i < 32; i++)
    {

    }

    return ans;
}

And now to count all the bit difference between subarray.

static int sumBitDifferences(int[] arr, int n)
{
    int ans = 0;  // Initialize result

    // traverse over all bits
    for (int i = 0; i < 32; i++)
    {
        // count number of elements with i'th bit set
        int count = 0;
        for (int j = 0; j < n; j++)
            if ((arr[j] & (1 << i)) == 0)
                count++;

        // Add "count * (n - count) * 2" to the answer
        ans += (count * (n - count) * 2);
    }

    return ans;
}