Compute the late payment fee
A billing system charges a fixed fee for the first overdue day and a smaller increment for each additional day.
- The first overdue day costs 2500.
- Each further day adds 500.
- Zero or fewer overdue days means no fee.
late_fee(days_late: int) → int
Where you start
def late_fee(days_late: int) -> int:
Worked examples
| Call | Result |
|---|---|
late_fee(1) | 2500 |
late_fee(2) | 3000 |
late_fee(5) | 4500 |
late_fee(0) | 0 |
Hint
Subtract one from the count, multiply the increment, and add the base — but only when positive.
Reference solution in Python
def late_fee(days_late: int) -> int:
if days_late <= 0:
return 0
return 2500 + (days_late - 1) * 500