Which month grew the most
A board slide calls out the month with the largest jump in revenue over the month before it.
- Compare each month with the one directly before it, in the order given.
- Only increases count; a month that fell is not a jump.
- On a tie, the earlier month wins.
- Fewer than two months, or no increase anywhere, gives null.
biggestJump(points: list<Point>) → string?
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
std::optional<std::string> biggestJump(std::vector<Point> points) {
}Worked examples
| Call | Result |
|---|---|
biggestJump(std::vector<Point>{Point{std::string("jan"), 100}, Point{std::string("feb"), 150}, Point{std::string("mar"), 160}}) | std::optional<std::string>(std::string("feb")) |
biggestJump(std::vector<Point>{Point{std::string("jan"), 100}, Point{std::string("feb"), 110}, Point{std::string("mar"), 120}}) | std::optional<std::string>(std::string("feb")) |
biggestJump(std::vector<Point>{Point{std::string("jan"), 100}, Point{std::string("feb"), 90}}) | std::nullopt |
biggestJump(std::vector<Point>{Point{std::string("jan"), 100}}) | std::nullopt |
Hint
Start from index 1 and keep the best strictly-greater difference, so ties keep the first one.
Reference solution in C++
std::optional<std::string> biggestJump(std::vector<Point> points) {
std::optional<string> bestMonth;
int bestJump = 0;
for (size_t i = 1; i < points.size(); i++) {
int jump = points[i].total - points[i - 1].total;
if (jump > bestJump) { bestJump = jump; bestMonth = points[i].month; }
}
return bestMonth;
}