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
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
int surchargeByMethod(std::map<std::string, int> surchargeRates, std::string method, int subtotal) {
}Worked examples
| Call | Result |
|---|---|
surchargeByMethod(std::map<std::string, int>{{std::string("visa"), 150}, {std::string("amex"), 300}}, std::string("amex"), 10000) | 300 |
surchargeByMethod(std::map<std::string, int>{{std::string("visa"), 150}}, std::string("paypal"), 5000) | 0 |
surchargeByMethod(std::map<std::string, int>{{std::string("visa"), 150}}, std::string("visa"), 8000) | 120 |
surchargeByMethod(std::map<std::string, int>{}, std::string("visa"), 1000) | 0 |
Hint
Map lookup, then a single integer division by ten thousand.
Reference solution in C++
int surchargeByMethod(std::map<std::string, int> surchargeRates, std::string method, int subtotal) {
auto it = surchargeRates.find(method);
int rate = it == surchargeRates.end() ? 0 : it->second;
return subtotal * rate / 10000;
}