How much of this can still be refunded
An agent asks to refund an amount against an order that may already have been partly refunded.
- Never refund more than what is left of the original payment.
- Never return a negative figure, whatever the inputs say.
- A request for zero or less refunds nothing.
RefundableAmount(paid: int, refunded: int, requested: int) → int
C# needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
public int RefundableAmount(int paid, int refunded, int requested) {
}Worked examples
| Call | Result |
|---|---|
RefundableAmount(1000, 200, 500) | 500 |
RefundableAmount(1000, 200, 900) | 800 |
RefundableAmount(1000, 1000, 50) | 0 |
RefundableAmount(1000, 0, -5) | 0 |
Hint
Work out what remains, then take the smaller of that and the request — floored at zero.
Reference solution in C#
public int RefundableAmount(int paid, int refunded, int requested) {
if (requested <= 0) return 0;
int left = paid - refunded;
if (left <= 0) return 0;
return Math.Min(left, requested);
}