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Problem: First Missing Positive

Explore how to solve the first missing positive integer problem by rearranging the array in place using cyclic sort. Understand how to achieve an efficient O(n) time and constant space solution, leveraging the array itself as a hash map to identify the missing value quickly.

Statement

Given an unsorted integer array nums, find and return the smallest positive integer that is not present in nums.

Your solution must run in O(n)O(n) time and use O(1)O(1) auxiliary space.

Constraints:

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