这道题的阶梯思路跟另外某个题的解题思路很类似！
Given an integer array nums, find the contiguous subarray within an array (containing at least one number) which has the largest product.
Example 1:
Input: [2,3,-2,4]
Output: 6
Explanation: [2,3] has the largest product 6.
Example 2:
Input: [-2,0,-1] Output: 0 Explanation: The result cannot be 2, because [-2,-1] is not a subarray.
link:{sourcedir}/_0152_MaximumProductSubarray.java[role=include]