Parcel discount band
A monthly contract discounts each parcel once the month's total reaches a threshold: every parcel from then on ships 15% cheaper.
- Ordinary rate applies below the threshold.
- A parcel is discounted once the running total, including it, has reached the threshold.
- The discounted rate is floor(cost × 85 / 100).
bulkDiscountBand(parcelCosts: list<int>, threshold: 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 bulkDiscountBand(std::vector<int> parcelCosts, int threshold) {
}Worked examples
| Call | Result |
|---|---|
bulkDiscountBand(std::vector<int>{100, 100, 100, 100}, 250) | 370 |
bulkDiscountBand(std::vector<int>{100, 100}, 200) | 185 |
bulkDiscountBand(std::vector<int>{100, 100, 100}, 1000) | 300 |
bulkDiscountBand(std::vector<int>{}, 0) | 0 |
Hint
Walk the values; once the running total crosses the threshold everything from that parcel on is discounted.
Reference solution in C++
int bulkDiscountBand(std::vector<int> parcelCosts, int threshold) {
int total = 0, running = 0;
for (int cost : parcelCosts) {
running += cost;
total += (running >= threshold) ? (cost * 85) / 100 : cost;
}
return total;
}