buy_and_sell_stocks_with_transaction_fee.cpp

/*
You are given an array prices where prices[i] is the price of a given stock on the ith day, and an integer fee representing a transaction fee.

Find the maximum profit you can achieve. You may complete as many transactions as you like, but you need to pay the transaction fee for each transaction.

Note: You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).

 

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.
Example 2:

Input: prices = [1,3,7,5,10,3], fee = 3
Output: 6
*/
 int maxProfit(vector<int>& prices, int fee) {
        
        int noStock = 0;
        int oneStock = -prices[0];
        
        for(int i=1; i<prices.size(); i++)
        {
            noStock = max(noStock, oneStock + prices[i] - fee);
            oneStock = max(oneStock, noStock - prices[i]);
        }
        
        return noStock;
    }