//QUICKSORT HELPER FUNCTIONS

//Konstantin Voevodski
//CS112A1 Spring 2008



void swapReferences(int[] a, int i1, int i2)
//swaps a[i1] and a[i2]
{
	int temp = a[i1];
	a[i1] = a [i2];
	a[i2]= temp;
}

int median3(int[] a, int left, int right)
//sorts a[left], a[center], a[right] in place
//swaps the median of the 3 (a[center], which is the pivot) with a[right-1]
//returns the pivot
{
	int center = (left + right) / 2;
	if(a[center] < a[left])
		swapReferences(a,center,left);
	if(a[right] < a [center])
		swapReferences(a,right,center);
	if(a[center] < a[left])
		swapReferences(a,center,left);
	swapReferences(a,center,right-1);
	return a[right-1];
}