function quickSort(data[], left, right)
{
    pivot = data[(left + right) / 2];
    l = left, r = right;
    while (l <= r)
    {
        while (l <= r && data[l] < pivot) 
        {
            ++l; 
        }
        while (r >= l && data[r] > pivot) 
        {
            --r; 
        }
        if (l == r && l == left) 
        {
            ++l; 
        }
        if (l == r && l == right) 
        {
            --r; 
        }
        if (l < r) 
        {
            swap(data[l], data[r]); 
            ++l; 
            --r; 
        }
        else
        {
            break;
        }
    }
    if (r - left + 1 >= 2) 
    {
        quickSort(data, left, r); 
    }
    if (right - r >= 2) 
    {
        quickSort(data, r + 1, right); 
    }
}