263.Ugly-Number

263. Ugly Number

题目地址

https://www.lintcode.com/en/problem/ugly-number/

题目描述

Write a program to check whether a given number is an ugly number`.

Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.

代码

public class Solution {
  public boolean isUgly(long num) {
    while (num % 2 == 0) {
      num /= 2;
    }

     while (num % 3 == 0) {
      num /= 3;
    }

     while (num % 5 == 0) {
      num /= 5;
    }

    return num == 1;
  }

}