Count the most common occurrence of subarray sum.
Constraints:
N <= 1e6; abs(ai) <= 1e6
Ex: Inp: 5 1 1 2 1 4 Out: 3 (there are 3 subarray with the sum of 4: (1, 1, 2), (1, 2, 1), (4) This question appears in ones of my friends competition and I have no idea how to solve it. Can someone help? Thanks.