A library charges for late books. Write library_fine(days_late) that returns the fine as a float:
- not late (0 or fewer days):
0.0 - 0.25 per day for each of the first 7 days
- 0.50 per day for every day after the seventh
- the fine never exceeds 10.0
Examples
Input: days_late = 0
Output: 0.0
Input: days_late = 3
Output: 0.75
Input: days_late = 10
Output: 3.25
Explanation: 7 * 0.25 + 3 * 0.50 = 1.75 + 1.50.
Constraints
-30 <= days_late <= 10000(integer)
Goals
- Combine a flat per-day rate with a higher rate after a threshold
- Apply a maximum with an if