Problem #4 : First missing positive integer

All problems are from https://www.dailycodingproblem.com/

 

Solution Codes : https://github.com/Kusin/DailyCoding

Kusin/DailyCoding

Daily coding Problem #4

 

After Solving this Problem, I searched this problem in google. Saw various solutions, found out my solution is unique. 

 

Many solutions used sort. Which makes their code O(n log n). However, my solution works in O(n), and constant space. Check it out.

This is the basic idea. I know that the explain is insufficient. 

Look carefully for the Algorithm

 

mp

 

Implementation