[LeetCode][C++] #152. Maximum Product Subarray

[Medium][Question]:

Given an integer array nums, find a contiguous non-empty subarray within the array that has the largest product, and return the product.

It is guaranteed that the answer will fit in a 32-bit integer.

A subarray is a contiguous subsequence of the array.

Example 1:

Input: nums = [2,3,-2,4]
Output: 6
Explanation: [2,3] has the largest product 6.

Example 2:

Input: nums = [-2,0,-1]
Output: 0
Explanation: The result cannot be 2, because [-2,-1] is not a subarray.

Constraints:

• 1 <= nums.length <= 2 * 104
• -10 <= nums[i] <= 10
• The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

My Solution[C++]:

[Ideas]: 跟Maximum Subarray概念差不多，只是要多一個最小值，因為乘上負數會變最小，但又再乘一次負數的話就會變最大，有點像給他一次敗部復活的機會。

另外要注意零，乘上就等於拋棄之前的繼承，從新開始算起。