1. Subarray Sum Equals K
Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k.

A subarray is a contiguous non-empty sequence of elements within an array.
2. Find Substring in a string problem.

Question

1. Subarray Sum Equals K
Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k.

A subarray is a contiguous non-empty sequence of elements within an array. 
2. Find Substring in a string problem.

Oracle