Given an array of integers *nums* and an integer *k*, return *the number of continuous subarrays whose sum equals k*.
nums = [array of integers], k = integer
integer (count of subarrays)
Example 1:
Input:
nums = [1,1,1] k = 2
Output:
2
Explanation:
Subarrays [1,1] (positions 0-1) and [1,1] (positions 1-2) sum to 2.
Example 2:
Input:
nums = [1,2,3] k = 3
Output:
2
Explanation:
Subarrays [1,2] and [3] both sum to 3.