Maximum Product Subarray

Medium, Dynamic Programming

Question

找到积最大的子序列

For example
序列[2,3,-2,4]的最大积序列为[2,3]积为6

Solution

与子序列最大和类似，不过需要考虑局部最大积和局部最小积，因为局部最小积为负数时与一个负数相乘可能成为最大积

class Solution(object):
    def maxProduct(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        maximum, minimum, maxAns = nums[0], nums[0], nums[0]
        for i in range(1,len(nums)):
            mx,mn = maximum,minimum
            maximum = max(max(nums[i],mx*nums[i]),mn*nums[i])
            minimum = min(min(nums[i],mx*nums[i]),mn*nums[i])
            maxAns = max(maximum,maxAns)
        return maxAns