122. Best Time to Buy and Sell Stock II

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).

 

股票可以买了卖掉  然后再买再卖掉  但是不能连续买2次再卖  买之后一定是接着卖

C++（6ms）：

class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int len = prices.size() ;
        int res = 0 ;
        for(int i = 1 ; i < len ; i++){
            res += max(prices[i] - prices[i-1] , 0) ;
        }
        return res ;
    }
};