Solution Review: Problem Challenge 2

Find the Smallest Missing Positive Number (medium)

Given an unsorted array containing numbers, find the smallest missing positive number in it.

Note: Positive numbers start from ‘1’.

Example 1:

Input: [-3, 1, 5, 4, 2]
Output: 3
Explanation: The smallest missing positive number is '3'

Example 2:

Input: [3, -2, 0, 1, 2]
Output: 4

Example 3:

Input: [3, 2, 5, 1]
Output: 4