Return the length of the shortest, non-empty, contiguous subarray of A with sum at least K.
If there is no non-empty subarray with sum at least K, return -1.
Example 1:
Input: A = [1], K = 1 Output: 1
Example 2:
Input: A = [1,2], K = 4 Output: -1
Example 3:
Input: A = [2,-1,2], K = 3 Output: 3
Note:
1 <= A.length <= 50000-10 ^ 5 <= A[i] <= 10 ^ 51 <= K <= 10 ^ 9