Best Time to Buy and Sell Stock ---- LeetCode

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.

解题思路：依次遍历数组prices，同时记录最低买入价，计算当日能获得的利润：当前卖出价-之前的最低买入价，判断是否为最大利润值。

public class Solution {
    public int maxProfit(int[] prices) {
           int len=prices.length;
      if(len==0||len==1){
      return 0;
      }       
           int lowIn=prices[0];
           int max=0;
           int i=1;           
           while(i<len){
          if(lowIn>prices[i-1]){
          lowIn=prices[i-1];
          }        
          int profit=prices[i]-lowIn;          
          if(profit>max){
          max=profit;
          }                    
          i++;
           } 
           
         return max;
    }
}