标签：des style blog color os io java ar strong
Say you have an array for which the ith element is the price of a given stock on dayi.
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).
public class Solution {
public int maxProfit(int[] prices)
{
if (prices == null || prices.length <= 1) return 0;
int LEN=prices.length;
int maxProfit = 0;
int i;
int smallPrice=prices[0];
int maxPrice=prices[LEN-1];
int[] profitsBy= new int[LEN+1];
int[] profitsSince= new int[LEN+1];
for (i = 0; i <= LEN; i++ )
{
profitsBy[i] = 0;
profitsSince[i] = 0;
}
for (i = 1; i < LEN;i++)
{
smallPrice=Math.min(smallPrice, prices[i]);
profitsBy[i]=Math.max(profitsBy[i-1], prices[i]-smallPrice);
}
for(i=LEN-2;i>=0;i--){
maxPrice=Math.max(maxPrice, prices[i]);
profitsSince[i]=Math.max(profitsSince[i+1],maxPrice-prices[i]);
}
for(i=0;i<LEN;i++){
maxProfit=Math.max(maxProfit, profitsBy[i]+profitsSince[i+1]);
}
return maxProfit;
}
}Best Time to Buy and Sell Stock III
标签：des style blog color os io java ar strong
原文地址：http://blog.csdn.net/jiewuyou/article/details/39135229
