Best Time to Buy and Sell Stock with Transaction Fee
Real-world version: Handling Fee ResaleThe statement here is our own: the same inputs, outputs and technique.
A scrap yard trades a single bale of copper at a time. quotes[i] is the price the bale
fetches on day i, and every completed sale is charged a flat handling fee of commission.
The yard may trade as often as it likes but never holds two bales: a purchase is only allowed with the yard clear, and a sale is only allowed with a bale on the ground. Buying and selling on the same day is permitted. The handling fee is charged once per sale, never on a purchase. A bale still on the ground when the days run out is simply left there and earns nothing.
Return the largest net cash position the yard can finish with, counting each sale as its price minus the purchase price minus the handling fee. Trading nothing at all leaves 0.
Examples
Example 1
- Input
- quotes = [4,7,5,11,6,12], commission = 3
- Output
- 7
Buy at 4 and sell at 11, then buy at 6 and sell at 12. The two sales bring in 7 and 6 before fees, and the two fees of 3 leave 7.
Example 2
- Input
- quotes = [1,4,3,6], commission = 2
- Output
- 3
Buy at 1 on day 0 and sell at 6 on day 3. That is 5 before the fee and 3 after the single fee of 2.
Constraints
- 1 <= quotes.length <= 5 * 10^4
- 1 <= quotes[i] < 5 * 10^4
- 0 <= commission < 5 * 10^4
The signature
The editor starts with this. It matches the parent problem's shape, so a solution that works here works on a standard judge unchanged.
def net_resale_gain(quotes: list[int], commission: int) -> int:public int netResaleGain(int[] quotes, int commission)Checking your plan…
How this problem was checked
- Passed: Reference solution run against 11 test cases: 11 passed
- Passed: 2 worked examples confirmed by running the code
- Passed: 0 eight-word sequences shared with the parent problem's text
- Passed: Agrees with an independent brute-force solution on random inputs
- Passed: Test set shown to catch deliberately broken solutions
- Passed: Reviewed by a separate quality pass
- Passed: Function arity matches the parent problem's