LeetCode之Best Time to Buy and Sell Stock

/*只能做一次交易。则对于在某天卖出的股票，获得最大盈利值的方法为：在这天之前中，股票价格最低的那天买进股票。比较每天卖出的股票，即可获得最大盈利。*/class Solution {public:    int maxProfit(vector<int>& prices) {        if(prices.size() <= 1) return 0;        int min_price(prices[0]), res(INT_MIN);        for(int i = 1; i < prices.size(); ++i){           min_price = min(min_price, prices[i-1]);           res = max(res, prices[i] - min_price);        }        return max(res, 0);    }};