Question

Let A be an array of 31 numbers consisting of a sequence of O's followed by a sequence of I's. The problem is to find the smallest index i such that A[i] is 1 by probing the minimum number of locations in A. The worst case number of probes performed by an optimal algorithm is ____

• A. 5

Answer 1

The correct option is A 5
Since 0 are followed by 1, so we have a sorted array of 0 and 1 and we can apply binary search algorithm with some modification, which will take maximum probes = $\lceil$$lo{g}_2$ 31$\rceil$ = 5