quick_sort.cpp

void QuickSort(int *a, int left, int right)
{
    int l = left, r = right;
    int pivot = a[(l + r) / 2];

    while(l <= r)
    {
        while(a[l] < pivot) l++;
    
        while(a[r] > pivot) r--;
     
        if(l <= r)
        {
            swap(a[l], a[r]);
            l++;
            r--;
        }
    }
     
    if(left < r) 
        Quick(a, left, r);
     
    if(l < right) 
        Quick(a, l, right);
}