[BOJ] 1735 분수 합 (JAVA)

https://www.acmicpc.net/problem/1735

1735번: 분수 합

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
	
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        long ja1 = Integer.parseInt(st.nextToken());
        long mo1 = Integer.parseInt(st.nextToken());
        st = new StringTokenizer(br.readLine(), " ");
        long ja2 = Integer.parseInt(st.nextToken());
        long mo2 = Integer.parseInt(st.nextToken());
        // end of input

        long mo3 = lcm(mo1, mo2);
        long ja3 = ja1 * mo3 / mo1 + ja2 * mo3 / mo2;

        while (true) {
            long gcd = gcd(ja3, mo3);
            if (gcd == 1) break;
            ja3 /= gcd;
            mo3 /= gcd;
        }

        System.out.print(ja3 + " " + mo3);

    }

    static long gcd(long a, long b) {
        if (a % b == 0) return b;
        return gcd(b, a % b);
    }

    static long lcm(long a, long b) {
        return a * b / gcd(a, b);
    }
	
}