Find the First K Missing Positive Numbers

Explore how to find the first K missing positive numbers from an unsorted array by applying cyclic sort techniques. Understand how to handle missing values beyond the array's range and implement a solution with optimal O(n + k) time complexity and O(n) space. This lesson helps you build a systematic approach to solving common coding interview problems involving arrays and missing positive integers.

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Statement

Given an unsorted integer array, arr, of size n and an integer k, find the first k missing positive integers from the array, ignoring all negative numbers and zeros.

If the array does not contain enough missing positive numbers, add the next consecutive positive integers, starting from the smallest number greater than the largest value in the array, until exactly k missing positive numbers have been found.

Return the list of the first k missing positive integers, sorted in ascending order.

Constraints:

$n =$ arr.length
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