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
Go 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
func refundableAmount(paid int, refunded int, requested int) int {
}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 Go
func refundableAmount(paid int, refunded int, requested int) int {
if requested <= 0 {
return 0
}
left := paid - refunded
if left <= 0 {
return 0
}
if requested < left {
return requested
}
return left
}