【LeetCode】263. Ugly Number

LeetCode-263

Links：https://leetcode.com/problems/ugly-number/

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. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.

Note that 1 is typically treated as an ugly number.

思路：除2,3,5直到不能整除，然后判断余数是不是1.

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

class Solution {

public:

bool isUgly(int num) {

while(num>=2 && num%2==0)num/=2;

while(num>=3 && num%3==0)num/=3;

while(num>=5 && num%5==0)num/=5;

return num==1;

}

};

【LeetCode】263. Ugly Number

Tagged on: LeetCode