[nomy99]

what if max is already overflown due to size of array (without even doing the lo + high calculation?) Then min + (max- min)/2 would be min + (smaller negative value) which would violate the min + (max-min)/2 <= max

[pk86]

Assuming the value of max passed in is "sane" (non-negative and within array bounds), it is strictly decreasing and should never overflow.