CodingMediumcod-g789

Subject HeapsLevel Mid–Senior~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

An ugly number is a positive integer whose only prime factors are 2, 3, and 5 (1 is considered ugly). Return the n-th ugly number in increasing order (1-indexed: the 1st is 1). 1 <= n.

Implement

nth_ugly_number(n: int) → int

Examples

in[10]out12

What 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.