Given an array nums and an integer k, return the number of non-empty subarrays that have a sum divisible by k. A subarray is a contiguous

Given an integer array nums return an array result such that result.length == nums.length and result[i] is the absolute difference between

Given a binary array nums and an integer goal, return the number of subarrays with a sum equal to goal. A subarray is a contiguous part of

Given an integer array nums, find the middle index in array, middleIndex. Note that you must find the leftmost middle index in nums array.

Prefix sum is an efficient and powerful technique, often useful in coding interviews and competitive coding. A prefix sum is the combined