Subarray Sum Equals K: Prefix Sum Hash Map

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. ### Input Format - First line contains space-separated integers representing `nums`. - Second line contains an integer `k`. ### Output Format - Print a single integer representing the count of subarrays summing to `k`. ### Constraints - `1 <= nums.length <= 2 * 10^4` - `-1000 <= nums[i] <= 1000` - `-10^7 <= k <= 10^7`