leetcode 714 - Best Time to Buy and Sell Stock with Transaction Fee

https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee/

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[0] = 1
Selling at prices[3] = 8
Buying at prices[4] = 4
Selling at prices[5] = 9
The total profit is ((8 - 1) - 2) + ((9 - 4) - 2) = 8.
Note:

0 < prices.length <= 50000.
0 < prices[i] < 50000.
0 <= fee < 50000.

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class Solution {
public:
int maxProfit(vector<int>& prices, int fee) {
int buy = -prices[0];
int sell = 0;

for (int i = 1; i < prices.size(); i++) {
sell = max(sell, buy + prices[i] - fee);
buy = max(buy, sell - prices[i]);
}

return sell;
}
};