一、最佳买卖股票时机含冷冻期  

309. 买卖股票的最佳时机含冷冻期 - 力扣（LeetCode）

public class Solution {

    public int maxProfit(int[] prices) {
        int len = prices.length;
        if (len < 2) {
            return 0;
        }

        int[] dp = new int[3];

        dp[0] = 0;
        dp[1] = -prices[0];
        dp[2] = 0;

        int pre0 = dp[0];
        int pre2 = dp[2];

        for (int i = 1; i < len; i++) {
            dp[0] = Math.max(dp[0], pre2);
            dp[1] = Math.max(dp[1], pre0 - prices[i]);
            dp[2] = dp[1] + prices[i];

            pre0 = dp[0];
            pre2 = dp[2];
        }
        return Math.max(dp[0], dp[2]);
    }
}

class Solution {
    public int maxProfit(int[] prices, int fee) {
        int maximumProfit = 0;
        int n = prices.length;
        int prevValue = prices[0] + fee;
        for (int i = 1; i < n; i++) {
            if (prices[i] + fee < prevValue) {
                prevValue = prices[i] + fee;
            } else if (prices[i] > prevValue) {
                maximumProfit += prices[i] - prevValue;
                prevValue = prices[i];
            }
        }
        return maximumProfit;
    }
}