题目：
题解：
class Solution {public int maxProfit(int k, int[] prices) {if (prices.length == 0) {return 0;}int n = prices.length;k = Math.min(k, n / 2);int[] buy = new int[k + 1];int[] sell = new int[k + 1];buy[0] = -prices[0];sell[0] = 0;for (int i = 1; i <= k; ++i) {buy[i] = sell[i] = Integer.MIN_VALUE / 2;}for (int i = 1; i < n; ++i) {buy[0] = Math.max(buy[0], sell[0] - prices[i]);for (int j = 1; j <= k; ++j) {buy[j] = Math.max(buy[j], sell[j] - prices[i]);sell[j] = Math.max(sell[j], buy[j - 1] + prices[i]); }}return Arrays.stream(sell).max().getAsInt();}
}