leetcode 152. 乘积最大子序列

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给定一个整数数组 nums ，找出一个序列中乘积最大的连续子序列（该序列至少包含一个数）。

示例 1:

输入: [2,3,-2,4]
输出: 6
解释: 子数组 [2,3] 有最大乘积 6。

示例 2:

输入: [-2,0,-1]
输出: 0
解释: 结果不能为 2, 因为 [-2,-1] 不是子数组。

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class Solution(object):
    def maxProduct(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        #dp transfer
        #max_local = max(max(max_local_pre*nums[i],nums[i]),min_local_pre*nums[i])
        #min_local = min(min(max_local_pre*nums[i],nums[i]),min_local_pre*nums[i])
        #max_global = max(max_local,max_global_pre)
        if not nums:return 0
        max_local = nums[0]
        min_local = nums[0]
        max_global = nums[0]
        for i in range(1,len(nums)):
            max_local_pre= max_local
            max_local = max(max(max_local*nums[i],nums[i]),min_local*nums[i])
            min_local = min(min(max_local_pre*nums[i],nums[i]),min_local*nums[i])
            max_global = max(max_local,max_global)
        return max_global