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First Missing Integer Interviewbit Solution

Problem Description:

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


Given [1,2,0] return 3,
[3,4,-1,1] return 2,
[-8, -7, -6] returns 1

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


Method 1:

Time Complexity: O(N) 
Space Complexity: O(N)

Method 2:

Time Complexity: O(NlogN)
Space Complexity: O(1)

Method 3:

Time Complexity: O(N)
Space Complexity: O(1)

2 commentaires

Chicku Singh
Chicku Singh
27 mai 2021

It looks in the code given above , first approach missed space constraints and second approach missed time constraint. ( As per InterviewBit problem statement)

29 mai 2021
En réponse à

Thank you @Chicku Singh for pointing that out. We have fixed the solution according to the original problem statement.

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