I recently gave a hiring test and was stuck on a particular problem. The problem is as follows:
You are given an array A of N elements and Q queries of the form L,R.
For every query find the first missing positive integer in the range A[L],A[L+1],A[L+2] ...... A[R].
N <= 10^6
Q <= 10^6
1<= A[i] <= 10^9
I know how to find the first missing positive in O(N) but don't know how to handle multiple queries in less time. Any help would be appreciated. Thanks