题解 | #买卖股票的最好时机 ii#

#找出所有最大值点和最小值点，作差就是所得利润
# 
# @param prices int整型一维数组 
# @return int整型
#
class Solution:
    def maxProfit(self, prices):
        # write code here

        buyPoint = []
        salePoint = []
        if len(set(prices)) == 1 or len(set(prices)) == 0:
            maxProfit = 0
            return maxProfit
        if len(prices) == 2:
            if prices[0] < prices[1]:
                maxProfit = prices[1] - prices[0]
                return maxProfit
            
        else:
            if prices[0] < prices[1]:
                buyPoint.append(prices[0])

            if prices[-1] > prices[-2]:
                salePoint.append(prices[-1])

            for i in range(1, len(prices)-1):

                if prices[i - 1] < prices[i] and prices[i] >= prices[i + 1]:
                    salePoint.append(prices[i])
                elif prices[i - 1] > prices[i] and prices[i] <= prices[i + 1]:
                    buyPoint.append(prices[i])
        # print(buyPoint,end="\n")
        # print(salePoint)
        maxProfit = 0
        for i in range(len(buyPoint)):
            
            maxProfit += (salePoint[i] - buyPoint[i])
        return maxProfit