Skip to main content

Ugly Number

Problem statement​

An ugly number is a positive integer whose prime factors are limited to 2, 3, and 5.

Given an integer n, return true if n is an ugly number.

Example 1:

Input: n = 6Output: trueExplanation: 6 = 2 × 3

Example 2:

Input: n = 1Output: trueExplanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.

Example 3:

Input: n = 14Output: falseExplanation: 14 is not ugly since it includes the prime factor 7.

Constraints:

  • -231 <= n <= 231 - 1

My solution​

/**
 * @param {number} n
 * @return {boolean}
 */
var isUgly = function(n) {
    if (n === 0) {
        return false
    }
    
    while (n % 5 === 0) {
        n /= 5
    }
    
    while (n % 3 === 0) {
        n /= 3
    }
    
    while (n % 2 === 0) {
        n /= 2
    }
    
    return n === 1;
};