Code Room
CodingMedium
Question
An ugly number is a positive integer whose only prime factors are 2, 3, and 5. The sequence begins 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, ... (1 is included by convention). Given n (1 <= n <= 1690), return the nth ugly number. The answer fits in a 64-bit integer.
Implement
nth_ugly_number(n: int) → intExamples
in
[10]out12What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Learn the concepts
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.
Run or narrate your approach, then ask the coach.