The questions states(on June/17):

Given an array nums and a target value k, find the maximum length of a subarray that sums to k. If there isn't one, return 0 instead.

Beware of the definition of "subarray", subarray don't have to be continuous.What is difference between subarray and contiguous subarray?

I tried test case: [1,-2,3], 4.

The top-voted solution and the OJ both return 0, rather than 2 ({1,3}).

Let's assume the question take non-continuous subarray into account, any idea on solving the non-continuous subarray case? It seems that O(N) time is hard.

Thanks in advance.