Say you have an array for which the ith element is the price of a given stock on day i.
Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times) with the following restrictions:
- You may not engage in multiple transactions at the same time (ie, you must sell the stock before you buy again).
- After you sell your stock, you cannot buy stock on next day. (ie, cooldown 1 day)
Example:
prices = [1, 2, 3, 0, 2] maxProfit = 3 transactions = [buy, sell, cooldown, buy, sell]
Credits:
Special thanks to @dietpepsi for adding this problem and creating all test cases.
1 public class Solution { 2 public int maxProfit(int[] prices) { 3 if(prices== null || prices.length <= 1) return 0; 4 int inclusive = 0;//可能包括今天的profit 5 int exclusive = 0;//不包括今天的profit 6 for(int i = 1; i < prices.length; i++){ 7 int profit = prices[i] - prices[i-1]; 8 int newinclusive = Math.max(inclusive+profit,exclusive); 9 int newexclusive = Math.max(inclusive,exclusive); 10 inclusive = newinclusive; 11 exclusive = newexclusive; 12 } 13 return Math.max(inclusive,exclusive); 14 } 15 }
这题很特别在cooldown。等二刷的时候再过一遍，看到有其他大神使用 状态机和分治的greedy 做的。