[java] 2609. 최대공약수와 최소공배수

import java.io.*;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());

        int a = Integer.parseInt(st.nextToken());
        int b = Integer.parseInt(st.nextToken());

        System.out.println(gcd(a,b));
        System.out.println(lcm(a,b));
    }
    public static int gcd(int a, int b){
        while (b != 0) {
            int temp = b;
            b = a % b;
            a = temp;
        }
        return a;
    }
    public static int lcm(int a, int b){
        return (a*b) / gcd(a,b);
    }
}

최대공약수는 유클리드 호제법을 생각해서 하기.