Best Time to Buy and Sell Stock

 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 =http://www.mamicode.com/ Integer.MAX_VALUE; 9         10         for (int i: prices) {11             minValue =http://www.mamicode.com/ Math.min(minValue, i);12             maxProfit = Math.max(maxProfit, i - minValue);13         }14         15         return maxProfit;16     }17 }