【LeetCode 122】关关刷题日记25-Best Time to Buy and Sell Stock II- 专知

【LeetCode 122】关关刷题日记25-Best Time to Buy and Sell Stock II

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关关的刷题日记 25 – Leetcode 122. 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).

这题目与121题的区别是，不限制买卖次数，可以进行多次交易。但是要求同一时间只能有一只股票在手里，下一次买股票之前必须把手里的股票卖掉。

思路

思路：和炒股的思想一样，最低点买入，最高点卖出，所以我们需要求单调递增区间的收益的累加和，时间复杂度O(n)。

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