122. Best Time to Buy and Sell Stock II 类别：贪心算法 难度：medium

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：

采用贪心算法，贪心策略为，当今天的收益比前一天收益高，则可当作股票昨天买入，今天卖出，这样所得的总收益是最高的。

程序：

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