Problems › TypeScript › reporting
The middle of a set of readings
A latency report quotes the median rather than the mean, because one slow request should not move the headline number.
- Sort first — the readings arrive in whatever order they were logged.
- An odd count has a single middle value.
- An even count takes the average of the two in the middle, which may be a half.
- No readings at all gives 0.
medianValue(values: list<int>) → float
Where you start
function medianValue(values: number[]): number {
}Worked examples
| Call | Result |
|---|---|
medianValue([3,1,2]) | 2 |
medianValue([1,2,3,4]) | 2.5 |
medianValue([7]) | 7 |
medianValue([]) | 0 |
Hint
After sorting, the two middles for an even count sit at n/2 - 1 and n/2.
Reference solution in TypeScript
function medianValue(values: number[]): number {
if (values.length === 0) return 0;
const s = values.slice().sort((a, b) => a - b);
const n = s.length;
const mid = Math.floor(n / 2);
return n % 2 === 1 ? s[mid] : (s[mid - 1] + s[mid]) / 2;
}