买卖股票的最佳时机III-动态规划123-python

没看答案，可以交易最多两次。

labuladong版

import sys

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
        n = len(prices)
        k = 2

        dp = [[[0] * 2 for _ in range(k+1)] for _ in range(n)]
        for i in range(n):
            dp[i][0][0] = 0
            dp[i][0][1] = -sys.maxsize
        for j in range(k+1):
            dp[-1][j][0] = 0
            dp[-1][j][1] = -sys.maxsize
        
        for i in range(n):
            for j in range(1, k+1):
                dp[i][j][0] = max(dp[i-1][j][0], dp[i-1][j][1] + prices[i])
                dp[i][j][1] = max(dp[i-1][j][1], dp[i-1][j-1][0] - prices[i])
        
        return dp[n-1][k][0]