122. Best Time to Buy and Sell Stock II
Say you have an array for which thei_thelement 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 (i.e., buy one and sell one share of the stock multiple times).
Note:You may not engage in multiple transactions at the same time (i.e., you must sell the stock before you buy again).
Input: [7,1,5,3,6,4] Output: 7 Explanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4. Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3.
Input: [1,2,3,4,5] Output: 4 Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4. Note that you cannot buy on day 1, buy on day 2 and sell them later, as you are engaging multiple transactions at the same time. You must sell before buying again.
Input: [7,6,4,3,1] Output: 0 Explanation: In this case, no transaction is done, i.e. max profit = 0.
- Greedy buy today's stock if tomorrow it will increase its price
class Solution(object): def maxProfit(self, prices): """ :type prices: List[int] :rtype: int """ profit = 0 for i, p in enumerate(prices[:-1]): if prices[i + 1] > p: profit += prices[i + 1] - p return profit
Code: One line
class Solution(object): def maxProfit(self, prices): """ :type prices: List[int] :rtype: int """ return sum([b - a if b > a else 0 for a, b in zip(prices, prices[1:])])