# 122-Best Time to Buy and Sell Stock II ###### tags: `Medium` ## Question ![](https://i.imgur.com/9ZGvSJh.png) https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/ ## Solution - 想法:因為可以當天賣出又買進,所以就算最低跟最高不是在前後兩天,一直買進賣出獲利一樣可以等於最低買最高賣,因此只做前後兩個差值的計算,就可以找到整個陣列最大的差值總和 ### C++ ```cpp= lass Solution { public: int maxProfit(vector<int>& prices) { int buy = prices[0]; int max = 0; int sell = 0; for(int i = 1; i < prices.size();i++) { sell = prices[i]; if(sell - buy > 0) { max += sell - buy; } buy = prices[i]; } return max; } }; ``` ### python ```python= class Solution: def maxProfit(self, prices): profit = 0 for i in range(len(prices)-1): if prices[i+1] - prices[i] > 0: profit += prices[i+1] - prices[i] return profit ```