Ugly Number

Write a program to check whether a given number is an ugly number.

Ugly numbers are positive numbers whose prime factors only include2, 3, 5. For example,6, 8are ugly while14is not ugly since it includes another prime factor7.

Note that1is typically treated as an ugly number.

分析

都是正数

class Solution {
    public boolean isUgly(int num) {
        if(num < 1)
            return false;
        if(num == 1)
            return true;
        int[] arr = {2,3,5};
        while(num != 1){
            boolean canMul = false;
            for(int i : arr){
                if(num % i == 0){
                    num /= i;
                    canMul = true;
                }
            }
            if(!canMul)
                return false;
        }
        return true;
    }
}