152. 乘积最大子数组

class Solution:
    def maxProduct(self, nums: List[int]) -> int:
        nums_length=len(nums)
        dp=[[0,0] for i in range(nums_length)]
        # 千万别写 dp=[[0,0]] *nums_length
        dp[0][0]=nums[0]
        dp[0][1]=nums[0]
        for i in range(1,nums_length):
            if nums[i]>=0:
                dp[i][0]=max(nums[i],dp[i-1][0]*nums[i])
                dp[i][1]=min(nums[i],dp[i-1][1]*nums[i])
            else:
                dp[i][0]=max(nums[i],dp[i-1][1]*nums[i])
                dp[i][1]=min(nums[i],dp[i-1][0]*nums[i])
        return max(dp,key=lambda x:x[0])[0]