Categories
interview

Random Pick Index

Given an input array that consists of numbers that may consist of duplicates, return the position of the number that is picked. This position has to be a “Random Pick Index” if the picked number has duplicates.

Example: Input: [1, 2, 4, 4, 4], Pick -> 4 then you can return 2, 3, or 4 randomly with equal probability. If 1 is the pick then 0 needs to be returned as there is only one occurrence at 0.