L517 Ugly Number

Write a program to check whether a given number is anuglynumber`.

Ugly numbersare positive numbers whose prime factors only include2,3,5. For example,6,8are ugly while14is not ugly since it includes another prime factor7.

Notice

Note that1is typically treated as an ugly number.

Example

Given num =8returntrue Given num =14returnfalse

public boolean isUgly(int num) {
    if (num < 1) {
        return false;
    } else if (num == 1) {
        return true;
    }

    while (num % 2 == 0) {
        num = num / 2;
    } 
    while (num % 3 == 0) {
        num = num / 3;
    } 
    while (num % 5 == 0) {
        num = num / 5;
    }

    return num == 1;
}