lc-188

public int maxProfit(int k, int[] prices) {
    int n = prices.length;
    if (n == 1) {
        return 0;
    }
    int[][][] dp = new int[n][k + 1][2];
    int ans = 0;
    int INF = Integer.MIN_VALUE/2;
    for (int i = 0; i < n; i++) {
        dp[i][0][0] = INF;
    }
    for (int i = 1; i <= k; i++) {
        dp[0][i][0] = INF;
        dp[0][i][1] = INF;
    }
    dp[0][1][0] = -prices[0];
    for (int i = 1; i < n; i++) {
        for (int j = 1; j <= k; j++) {
            dp[i][j][0] = Math.max(dp[i - 1][j - 1][1] - prices[i], dp[i - 1][j][0]);//买入
            dp[i][j][1] = Math.max(dp[i - 1][j][0] + prices[i], dp[i - 1][j][1]);//卖出
            ans = Math.max(dp[i][j][0], ans);
            ans = Math.max(dp[i][j][1], ans);
        }
    }
    return ans;
}