27. 콜라츠 추측

class Solution {
    public int solution(int num) {
        int answer = 0;        
        
        for ( int i = 0; i < 500; i++)
        {
            if ( num == 1)
            {
                return answer;
            }
            
            if ( num % 2 == 0 )
            {
                num /= 2;
            }
            else if ( num % 2 == 1 )
            {   
                num = (num * 3) + 1;
            }
            answer++;
        }        
        answer = -1;        
        
        return answer;
    }
}