Ugly number

Math

43.2% acceptance

Jan 12, 2026

3818

1791

An ugly number is a positive integer which does not have a prime factor other than 2, 3, and 5. Given an integer n, return true if n is an ugly number.

Solution

Rust

Time O(n²)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn is_ugly(n: i32) -> bool {
    if n <= 0 {
      return false;
    }
    
    let mut n = n;
    for factor in [2, 3, 5] {
      while n % factor == 0 {
        n /= factor;
      }
    }
    
    n == 1
  }
}