121.买卖股票的最佳时机
class Solution {public int maxProfit(int[] prices) {int minprice = Integer.MAX_VALUE;int maxprofit = 0;for(int i =0;i<prices.length;i++){if(prices[i] < minprice){minprice = prices[i]; //找到最小值}else if(prices[i] - minprice > maxprofit){ //记录之后与最小值之间得差值maxprofit = prices[i] - minprice; }}return maxprofit;}
}