#Arrays

Write code to find the Kth largest and Kth smallest elements in an unsorted array.

Given an unsorted integer array, find the first missing positive integer. Describe your approach to solving this problem efficiently.

Explain how JavaScript's Array.prototype.reduce() works. What are the roles of the accumulator, current element, and initial value? Walk through the given example.

Solve a problem similar to finding pairs with the minimum absolute difference in an array. The task is to identify such pairs efficiently.

Given an array of positive integers and a target value, find the minimal length of a contiguous subarray of which the sum is greater than or equal to the target value. If no such subarray exists, return 0. Example: Input: nums = [2,3,1,2,4,3], target = 7. Output: 2.