Consider the following line of code from both quicksort and mergesort algorithms in Lewis and Chase. There is a rare case where this line returns an invalid index - what is it? How can the line be rewritten?

int middle = (min + max) / 2;

Some of the actual code:

private static >

int partition(T[] data, int min, int max)

{

T partitionelement;

int left, right;

int middle = (min + max) /2;

......

}