[leetode] 122. Best Time to Buy and Sell Stock II

Question:

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).

Solution:

这算是一个贪心算法吧，只要昨天的价格比今天的低，那么就能赚钱，那就昨天买入今天卖出就可以了。

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