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 if (prices.length<=1) { 4 return 0; 5 } 6 7 int[] left = new int[prices.length]; 8 int[] right = new int[prices.length]; 9 int min = prices[0]; 10 for (int i = 1; i < prices.length; i++) { 11 left[i] = left[i - 1] > prices[i] - min ? left[i - 1] : prices[i] - min; 12 min = min < prices[i] ? min : prices[i]; 13 } 14 15 int max = prices[prices.length - 1]; 16 for (int i = prices.length - 2; i >= 0; i--) { 17 right[i] = right[i + 1] > max - prices[i] ? right[i + 1] : max - prices[i]; 18 max = max > prices[i] ? max : prices[i]; 19 } 20 int sum = Integer.MIN_VALUE; 21 for (int i = 0; i < left.length; i++) { 22 sum = sum > left[i] + right[i] ? sum : left[i] + right[i]; 23 } 24 return sum; 25 } 26 }