Best time to buy and buy stock III

Say you have an array for whichITh element is the price of a given stock on dayI.

Design an algorithm to find the maximum profit. You may complete at mostTwoTransactions.

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

The prototype of this question: http://blog.csdn.net/huruzun/article/details/39429631 utilizes dynamic planning because it is up to two transactions, using an array to record each position on the left profit another position on the right profit

The array L [I] records the maximum profit of price [0. I,

The array R [I] records the maximum profit of price [I. N.

It is known that L [I] and L [I + 1] is simple. It is also known that R [I] is also easy to find R [I-1.

Finally, we use O (n) Time to find the largest L [I] + R [I], that is, the question.

    public class Solution {    public int maxProfit(int[] prices) {        if (prices == null || prices.length == 0) {            return 0;        }        int n = prices.length;        int[] left = new int[n];        int[] right = new int[n];        int min = prices[0];        for (int i = 1; i < n; i++) {            left[i] = left[i - 1] > prices[i] - min ? left[i - 1] : prices[i] - min;            min = min < prices[i] ? min : prices[i];        }        int max = prices[n - 1];        for (int i = n - 2; i >= 0; i--) {            right[i] = right[i + 1] > max - prices[i] ? right[i + 1] : max - prices[i];            max = max > prices[i] ? max : prices[i];        }        int value = 0;        for (int i = 0; i < n; i++) {            value = value > left[i] + right[i] ? value : left[i] + right[i];        }        return value;    }}

Best time to buy and buy stock III