LeetCode-Best Time to Buy and Sell Stock II

题目
Say you have an array for which the ith element is the price of a given stock on day i.
Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times). However, you may not engage in multiple transactions at the same time (ie, you must sell the stock before you buy again).

思路1
题目中说不能同时买和卖，所以可以求出极高点和极低点，然后求差获得总的收益…好麻烦…太简单，懒得写了

class Solution {public:    int maxProfit(vector<int>& prices) {        int profit=0;        int days=prices.size();        int yesterday=INT_MAX;        for(int i=0;i<days;i++){            int earn=prices[i]-yesterday;            yesterday=prices[i];            if(earn>0){                profit+=earn;            }        }        return profit;    }};