void quickSort(int*, int, int);
int partition(int*, int, int);

void quickSort(int *a, int l, int r)
{
	int j;

	if( l < r ) 
	{
		j = partition( a, l, r);
		quickSort( a, l, j-1);
		quickSort( a, j+1, r);
	}
	
}

int partition(int *a, int l, int r) {
	int pivot, i, j, t;
	pivot = a[l];
	i = l; j = r+1;
		
	while( 1)
	{
		do ++i; while( a[i] <= pivot && i <= r );
		do --j; while( a[j] > pivot );
		if( i >= j ) break;
		t = a[i]; a[i] = a[j]; a[j] = t;
	}
	t = a[l]; a[l] = a[j]; a[j] = t;
	return j;
}