Subarray Sum Equals K (Variant)

Given an integer array nums and an integer k, return the number of contiguous subarrays whose sum equals k. Notes: Subarray must be contiguous. The array may contain negative numbers. Constraints 1 <= len(nums) <= 2e5 -1e4 <= nums[i] <= 1e4 -1e9 <= k <= 1e9 Examples Input: nums = [1,1,1], k = 2 Output: 2 Input: nums = [1,2,3], k = 3 Output: 2 Example Input 3 1 1 1 2 Output 2