263. Ugly Number

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263. Ugly Number

Description

Difficulty: Easy

Related Topics: Math

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:

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

Example 2:

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

Example 3:

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

Constraints:

  • -231 <= n <= 231 - 1

Hints/Notes

  • N/A

Solution

Language: C++

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class Solution {
public:
    bool isUgly(int n) {
        if (n == 0) return false;
        while (n % 2 == 0) n /= 2;
        while (n % 3 == 0) n /= 3;
        while (n % 5 == 0) n /= 5;
        return n == 1;
    }
};