DIY: Subarray Sum Equals K

Problem statement

In this scenario, you will be provided with an array of integers and a single integer k. Your task is to find the total number of contiguous subarrays whose sum is equal to the integer value of k.

Input

The input is an array of integers and k. The following is an example input:

[1,2,3,4,5,6,7,1,23,21,3,1,2,1,1,1,1,1,12,2,3,2,3,2,2], 2

Output

The output is the total number of subarrays whose sum is equal to k. The following is an example output:

10

Coding exercise

You need to implement the function subarray_sum(arr, k), where arr is an array of integers and k is the value you need to check for. The function returns a single integer value representing the number of contiguous subarrays whose sum is equal to k.