Best Time to Buy and Sell Stock

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.

Solution 1:

min记录最小买入价

maxProfit记录最大利润

遍历array，不断更新最小买入价，计算更新最大利润

 1 public class Solution {
 2     public int maxProfit(int[] prices) {
 3         if (prices == null) {
 4             return 0;
 5         }
 6
 7         int maxProfit = 0;
 8         int minValue = Integer.MAX_VALUE;
 9
10         for (int i: prices) {
11             minValue = Math.min(minValue, i);
12             maxProfit = Math.max(maxProfit, i - minValue);
13         }
14
15         return maxProfit;
16     }
17 }

GitHub代码链接