leetcode-714. 买卖股票的最佳时机含手续费

原始思路

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class Solution {
    public int maxProfit(int[] prices, int fee) {
        int n = prices.length;
        if (n < 2) {
            return 0;
        }

        // 定义dp数组
        int[][] dp = new int[n][2];
        dp[0][0] = 0;
        dp[0][1] = -prices[0];

        for (int i = 1; i < n; i++) {
            dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i] - fee);
            dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]);
        }

        return dp[n - 1][0];
    }
}

状态压缩

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class Solution {
    public int maxProfit(int[] prices, int fee) {
        int n = prices.length;
        if (n < 2) {
            return 0;
        }

        // 定义dp数组
        int[] dp = new int[2];
        dp[0] = 0;
        dp[1] = -prices[0];

        for (int i = 1; i < n; i++) {
            dp[0] = Math.max(dp[0], dp[1] + prices[i] - fee);
            dp[1] = Math.max(dp[1], dp[0] - prices[i]);
        }

        return dp[0];
    }
}