leetcode -- Best Time to Buy and Sell Stock III TODO

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 at most two transactions.

Note:
You may not engage in multiple transactions at the same time (ie, you must sell the stock before you buy again).

 

 1 public class Solution {
 2     public int maxProfit(int[] prices) {
 3         // Start typing your Java solution below
 4         // DO NOT write main() function
 5         if(prices.length == 0){
 6             return 0;
 7         }
 8         int result = Integer.MIN_VALUE;
 9         int[] profits = new int[prices.length];
10         int min = Integer.MAX_VALUE, maxBeforeI = Integer.MIN_VALUE;
11         for (int i = 0; i < prices.length; i++) {
12             if (prices[i] < min) {
13                 min = prices[i];
14             }
15             if (prices[i] - min > maxBeforeI) {
16                 maxBeforeI = prices[i] - min;
17             }
18             profits[i] = maxBeforeI;
19         }
20         int max = Integer.MIN_VALUE;
21         for (int i = prices.length - 1; i >= 0; i--) {
22             if (prices[i] > max) {
23                 max = prices[i];
24             }
25 
26             int profit = max - prices[i];
27 
28             if (profit + profits[i] > result) {
29                 result = profit + profits[i];
30             }
31         }
32         return result;
33     }
34 }

 

m transactions solution not understand

http://discuss.leetcode.com/questions/287/best-time-to-buy-and-sell-stock-iii

posted @ 2013-08-17 20:46  feiling  阅读(299)  评论(0)  编辑  收藏  举报