题目

题解

class Solution:def maxProfit(self, prices: List[int]) -> int:N = len(prices)# 状态定义 dp[i][j][k]代表在第i天，被允许完成j次交易时，持有或者不持有的最大利润。k=0代表不持有，k=1代表持有dp = [[[0 for k in range(2)] for j in range(3)] for i in range(N)]for i in range(N):# 注意遍历范围 for j in range(1, 3):# badcaseif i - 1 == -1:dp[i][j][0] = 0dp[i][j][1] = -prices[i]else: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][2][0]