Ugly Number

1. Problem Statement

• Ugly Number
• My Code

2. Algorithm Design and Approach

• greedy
• Using While Loop to check prime number in n

3. Implementation

#include <iostream>
using namespace std;

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

4. Example Walkthrough

n = 6

• true

n = 1

• false

n = 14

• false

5. Conclusion

• ”%=” Operator changes value of origin left value
• Using “If” and “&&” Operator is not good for minimize time complexity.