Just simple quicksort with right element as pivot

quicksort.cpp

void quicksort(int arr[], int left, int right)
{
    if (left < right) {
        int pivot = arr[right];
        int i = left - 1;

        for (int j = left; j <= right-1; j++)
        {
            if (arr[j] <= pivot)
            {
                i++;
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }
        int temp = arr[i + 1];
        arr[i + 1] = arr[right];
        arr[right] = temp;

        quicksort(arr, left, i);
        quicksort(arr, i+1, right);
    }
}