挺难的题。recursive需要好好想。
public class Solution {
public int maxProfit(int k, int[] prices) {
if(k<=0 || prices == null || prices.length==0)
return 0;
int len = prices.length;
if(k >= len/2) {
int max_prof = 0;
for(int j=1; j<len; j++) {
if(prices[j] > prices[j-1])
max_prof += prices[j]-prices[j-1];
}
return max_prof;
}
int dp[][] = new int[k+1][len];
for(int i=1; i<=k; i++) {
int max_tmp = dp[i-1][0] - prices[0];
for(int j=1; j<len; j++) {
dp[i][j] = Math.max(dp[i][j-1], max_tmp + prices[j]);
max_tmp = Math.max(max_tmp, dp[i-1][j] - prices[j]);
}
}
return dp[k][len-1];
}
}
