// Copy-and_pasted from partition in qsort_1a1.c 
// function name partition is renamed to part.
// parameters l and r are changed to left and right respectively.
size_t part(int * data, int left, int right) 
{
	int i = left + 1, j = right;
	int pivot = data[left];	
	while (i <= j) 
	{
		while (pivot < data[j])
			j--;
		if (j == left)
			return left;
		while (i < right && pivot > data[i])
			i++;
		if (i == j) break;
		if (i < j)
			swap(&data[i], &data[j]);
	}
	swap(&data[left], &data[j]);	
	return j;
}