Payment method surcharge
Certain payment methods carry a surcharge. Look up the percentage and apply it to the subtotal.
- Rates in the map are basis points — hundredths of a percent.
- The surcharge is floor(subtotal × rate / 10000).
- An unknown method means no surcharge.
surchargeByMethod(surchargeRates: map<string, int>, method: string, subtotal: 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 surchargeByMethod(surchargeRates map[string]int, method string, subtotal int) int {
}Worked examples
| Call | Result |
|---|---|
surchargeByMethod(map[string]int{"visa": 150, "amex": 300}, "amex", 10000) | 300 |
surchargeByMethod(map[string]int{"visa": 150}, "paypal", 5000) | 0 |
surchargeByMethod(map[string]int{"visa": 150}, "visa", 8000) | 120 |
surchargeByMethod(map[string]int{}, "visa", 1000) | 0 |
Hint
Map lookup, then a single integer division by ten thousand.
Reference solution in Go
func surchargeByMethod(surchargeRates map[string]int, method string, subtotal int) int {
rate := 0
if r, ok := surchargeRates[method]; ok {
rate = r
}
return subtotal * rate / 10000
}