[leetcode]263. Ugly Number

[leetcode]263. Ugly Number

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Analysis

paper的噩梦似乎又要开始了~—— [ummmm~]

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.
判断一个数是否只含有2、3、5三个因子。

Implement

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