Leetcode•May 09, 2025
Ugly Number
Hazrat Ali
Leetcode
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.
Example 1:
Input: n = 6 Output: true Explanation: 6 = 2 × 3
Example 2:
Input: n = 1 Output: true Explanation: 1 has no prime factors.
Example 3:
Input: n = 14 Output: false Explanation: 14 is not ugly since it includes the prime factor 7.
Solution
/**
* @param {number} num
* @return {boolean}
*/
const isUgly = num => {
for (let p of [2, 3, 5]) {
while (num && num % p == 0) num /= p;
}
return num === 1;
};