从分歧和征服方法中找到索引

Question

我正在使用划分和征服方法练习的练习 https://leetcode.com/problems/bests/best -Time-to-to-buy and-sell-sell-sell-stock-iii/

def calcchanges(price):
    changes = []
    for i in range(len(price)-1):
        delta = round(price[i+1] - price[i],3)
        changes.append(delta)
    return changes

def MSSDAC(A, low=0, high=None):
    if high==None:
        high = len(A)-1

    if low==high:
        if A[low]>0:
            return A[low]
        else:
            return 0
    mid = (low+high)//2
    maxleft = MSSDAC(A, low, mid)
    maxright = MSSDAC(A, mid+1, high)
    maxleft2center = left2center = 0
    for i in range(mid, low-1, -1):
        left2center += A[i]
        maxleft2center = max(left2center, maxleft2center)
    maxright2center = right2center = 0
    for i in range(mid+1, high+1):
        right2center += A[i]
        maxright2center = max(right2center, maxright2center)
    return max(maxleft, maxright, maxleft2center+maxright2center)

#This code is only focusing on 1 transaction
""" Example 2
Input: prices = [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.
"""
prices = [1,2,3,4,5]
changes = calcchanges(prices)
maxprofit = MSSDAC(changes)
print(maxprofit)

我的问题是，有可能获得一天吗？，在第1天购买并在第5天出售？

通过使用Divide和Conquer，我将列表递归分配。因此，我有点迷失了如何跟踪索引。