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Solution: First Missing Positive

Explore how to identify the smallest missing positive integer from an unsorted array using cyclic sort. This lesson teaches you to reorder elements in place to achieve optimal linear time and constant space complexity, helping you solve a common interview problem efficiently.

Statement

Given an unsorted integer array, nums, return the smallest missing positive integer. Create an algorithm that runs with an O(n)O(n) time complexity and utilizes a constant amount of space.

Note: The smallest missing positive isn’t the first positive number that’s missing in the range of elements in the input, but the first positive number that’s missing if we start from 11.

Constraints:

  • 11 \leq nums.length 105\leq 10^5 ...