[Python手撕]买卖股票（交易2次）

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
        n = len(prices)
        dp = [[[0, 0] for i in range(3)] for j in range(n)]

        for j in range(1, 3):
            dp[0][j][1] = -prices[0]

        for i in range(1, n):
            for j in range(1, 3):
                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[-1][-1][0]