LeetCode 0263 - Ugly Number

Ugly Number

Desicription

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:

代码语言：javascript复制

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

Example 2:

代码语言：javascript复制

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

Example 3:

代码语言：javascript复制

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: [−2^31, 2^31 − 1].

Solution

代码语言：javascript复制

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

bit include integer numbers range

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