714. 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.
  • Rust Solution

    struct Solution;
    
    impl Solution {
        fn max_profit(prices: Vec<i32>, fee: i32) -> i32 {
            let n = prices.len();
            let mut cash = 0;
            let mut hold = -prices[0];
            for i in 1..n {
                cash = cash.max(hold + prices[i] - fee);
                hold = hold.max(cash - prices[i]);
            }
            cash
        }
    }
    
    #[test]
    fn test() {
        let prices = vec![1, 3, 2, 8, 4, 9];
        let fee = 2;
        let res = 8;
        assert_eq!(Solution::max_profit(prices, fee), res);
    }
    

    Having problems with this solution? Click here to submit an issue on github.