## Description

Your are given an array of integers prices, for which the i-th element is the price of a given stock on day i; and a non-negative integer fee representing a transaction fee.

You may complete as many transactions as you like, but you need to pay the transaction fee for each transaction. You may not buy more than 1 share of a stock at a time (ie. you must sell the stock share before you buy again.)

Return the maximum profit you can make.

Example 1:

Input: prices = [1, 3, 2, 8, 4, 9], fee = 2
Output: 8
Explanation: The maximum profit can be achieved by:
Buying at prices = 1Selling at prices = 8Buying at prices = 4Selling at prices = 9The total profit is ((8 - 1) - 2) + ((9 - 4) - 2) = 8.


Note:

0 < prices.length <= 50000.

0 < prices[i] < 50000.

0 <= fee < 50000.

## Solutions

### 1. DP

# Time: O(n)
# Space: O(n)
class Solution:
def maxProfit(self, prices: List[int], fee: int) -> int:
if not prices or len(prices) <= 1:
return 0
n = len(prices)
buy = [0 for _ in range(n)]
sell = [0 for _ in range(n)]