Say you have an array for which the ith 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.
Example 1:
Input: [7, 1, 5, 3, 6, 4] Output: 5 max. difference = 6-1 = 5 (not 7-1 = 6, as selling price needs to be larger than buying price)
Example 2:
Input: [7, 6, 4, 3, 1] Output: 0 In this case, no transaction is done, i.e. max profit = 0.
题意：买入卖出股票。你只能先买一只，然后选择时机卖出。求能赚到的最大利润。
public class Solution {
public int maxProfit(int[] prices) {
if(prices==null || prices.length<2)return 0;
int Min=prices[0];
int ret=0;
for(int i=1;i<prices.length;i++){
Min=Math.min(Min,prices[i]);
ret=Math.max(ret,prices[i]-Min);
}
return ret;
}
}Leetcode 121. Best Time to Buy and Sell Stock JAVA语言
原文：http://fulin0532.blog.51cto.com/6233825/1910661