263. Ugly Number #

题目 #

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 is typically treated as an ugly number.
• Input is within the 32-bit signed integer range: [−2^31, 2^31 − 1].

题目大意 #

判断一个数字是否是“丑陋数字”，“丑陋数字”的定义是一个正数，并且因子只包含 2，3，5 。

解题思路 #

依照题意要求做即可。

代码 #

package leetcode

func isUgly(num int) bool {
	if num > 0 {
		for _, i := range []int{2, 3, 5} {
			for num%i == 0 {
				num /= i
			}
		}
	}
	return num == 1
}