1.问题

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

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.

分析：假设你有一个数组，其中第i个元素是一个给定股票第i天的价格。只能进行一次交易，寻找最大利润。

找到数组中最小的元素与最大的元素，最大值要在最小值之前。

设两个变量，一个存储当前找到的最小值，一个存储当前最大的利润差值，遍历数组。

2、解答

public class Solution {public int maxProfit(int[] prices) {int maxout = 0;int min = Integer.MAX_VALUE;for(int i = 0; i<prices.length;i++){if(prices[i]<min)min = prices[i];if(prices[i]-min >maxout)maxout = prices[i] - min;}return maxout;}
}