263. Ugly Number

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.

Example 1:

Input: 6
Output: true
Explanation: 6 = 2 × 3

Example 2:

Input: 8
Output: true
Explanation: 8 = 2 × 2 × 2

Example 3:

Input: 14
Output: false 
Explanation: 14 is not ugly since it includes another prime factor 7.

Note:

1. 1 is typically treated as an ugly number.

2. Input is within the 32-bit signed integer range: [−231, 231 − 1].

bool isUgly(int num) {
    if (num <= 0) return false;
    vector<int> factor = {2, 3, 5};
    for (int f : factor) {
        while (num % f == 0) num /= f;
    }
    return num == 1;
}