Best Time to Buy and Sell Stock C#

Say you have an array for which the i^th element is the price of a given stock on dayi.

If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.

题意：给定一个数组表示第N天的股票价格，只能买卖一次，找到最大收益，即两天的价格差最大。

解析：简单的动态规划问题，定义一个数组，记录当前prices[i]的前面 i - 1 个prices的最低值，并计算在以当前prices[i] sell时的profit是多少，一遍循环即可解决问题。

代码实现：

 

public class Solution    {        public int MaxProfit(int[] prices)        {            if (prices.Length <= 1)                return 0;            int[] low = new int[prices.Length];            int profits = 0;            low[0] = prices[0];            for (int i = 1; i < prices.Length; i++)            {                if (prices[i] < low[i - 1])                    low[i] = prices[i];                else                    low[i] = low[i - 1];                profits = profits > (prices[i] - low[i - 1]) ? profits : prices[i] - low[i - 1];            }            return profits;        }    }