比昨天的相比还是简单些

309. 最佳买卖股票时机含冷冻期

四个状态，买入、今天卖出、冷冻、卖出状态

class Solution {
public:
    // 0 买入
    // 1 今天卖出
    // 2 冷冻
    // 3 卖出状态
    int maxProfit(vector<int>& prices) {
        int n = prices.size();
        vector<vector<int>> dp(n, vector<int>(4));
        dp[0][0] = -prices[0];
        for (int i = 1; i < n; i ++)
        {
            dp[i][0] = max(dp[i-1][0], max(dp[i-1][2] - prices[i], dp[i-1][3] - prices[i]));
            dp[i][1] = dp[i-1][0] + prices[i];
            dp[i][2] = dp[i-1][1];
            dp[i][3] = max(dp[i-1][3], dp[i-1][2]);
        }
        return max(dp[n-1][1], max(dp[n-1][2], dp[n-1][3]));
    }
};

714. 买卖股票的最佳时机含手续费

class Solution {
public:
    // 0持有 1卖
    int maxProfit(vector<int>& prices, int fee) {
        int n = prices.size();
        vector<vector<int>> dp(n, vector<int> (2));
        dp[0][0] = -prices[0];
        for (int i = 1; i < n; i ++)
        {
            dp[i][0] = max(dp[i-1][0], dp[i-1][1] - prices[i]);
            dp[i][1] = max(dp[i-1][1], dp[i-1][0] + prices[i] - fee);
        }
        return max(dp[n-1][0], dp[n-1][1]);
    }
};