Introduction - If you have any usage issues, please Google them yourself
given a sorted ( smallest to largest) array A of n distinct integers which can be positive, negative, or zero. You want to check whether or not there is an index i that matches the corresponding item A[i]. If exists, return the item, else, return -1.
Design the fastest algorithm that you can for solving this problem. O(n) solution is not the most efficient solution for this problem. The required solution is better than O(n).