Find the First K Missing Positive Numbers

Explore how to identify the first k missing positive integers from an unsorted array while ignoring negatives and zeros. Learn to apply cyclic sort concepts to achieve an optimal O(n + k) time solution, understanding key approaches to handle missing and consecutive numbers in coding interviews.

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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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