Solving First Missing Positive in go. Please try yourself first to solve the problem and submit your implementation to LeetCode before looking into solution.

Problem Description

Given an unsorted integer array, find the smallest missing positive integer.

Example 1: 

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

Example 2: 

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

Example 3: 

Input: [7,8,9,11,12]  
Output: 1

Note:

Your algorithm should run in O(n) time and uses constant extra space.

See the full details of the problem First Missing Positive at LeetCode

Originally posted at: @github.com/halfrost/LeetCode-Go