LeetCode-Go/website/content/ChapterFour/0263.Ugly-Number.md

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 {
	for i := 2; i < 6 && num > 0; i++ {
		for num%i == 0 {
			num /= i
		}
	}
	return num == 1
}