Solution: Find k Smallest Elements in an Array

Statement

Given an unsorted array arr and an integer k, find the k smallest elements from the array using a Heap.

Constraints:

• $1 \leq$ arr.length $\leq 10^3$
• $1 \leq$ k $\leq 10^3$
• $-10^5 \leq$ arr[i] $\leq 10^5$