N15651 - N과 M (3)

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

public class Main {
    final static BufferedWriter BW = new BufferedWriter(new OutputStreamWriter(System.out));
    final static StringBuffer sb = new StringBuffer();
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        solution(1, sc.nextInt(), sc.nextInt(), "");
        BW.write(sb.toString());
        BW.close();
    }

    public static void solution(int from, int to, int m, String s) {
        if (m == 1) {
            for (int i = from; i <= to; i++)
                sb.append(s + i + "\n");
        } else {
            for (int i = from; i <= to; i++)
                solution(from, to, m - 1, s + i + " ");
        }
    }
}