Leetcode 188. Best Time to Buy and Sell Stock IV

Leetcode 188. Best Time to Buy and Sell Stock IV
很久很久没有刷到这么好的题目了，很经典的DP题目，动态规划简而言之，就是要学会分情况讨论。

public class Solution {public static void main(String[] args){Solution s = new Solution();int[] k = {6,1,3,2,4,7};int r = s.maxProfit(2, k);System.out.println(r);}    public int maxProfit(int k, int[] prices) {        int len = prices.length;                   if(k>=len){            int res = 0;            for(int i=1;i<len;i++){                if(prices[i]>prices[i-1]){                    res += prices[i] - prices[i-1];                }            }            return res;        }        int[][] local = new int[len][k+1];        int[][] global = new int[len][k+1];         for(int i=1;i<len;i++){            int diff = prices[i] - prices[i-1];            int res = prices[i] > prices[i-1] ? diff:0;            for(int j=1;j<=k;j++){                local[i][j] = global[i-1][j-1]+res>local[i-1][j]+diff?global[i-1][j-1]+res:local[i-1][j]+diff;                global[i][j] = global[i-1][j]>local[i][j]?global[i-1][j]:local[i][j];            }        }        return global[len-1][k];    }}