N과 M （2）.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Main {
    static int[] arr;
    static int n, m;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        n = Integer.parseInt(st.nextToken());
        m = Integer.parseInt(st.nextToken());

        arr = new int[m];
        func(1, 0);

    }

    static void func(int now, int cnt) {
        if (cnt == m) {
            for (int i = 0; i < m; i++) {
                System.out.print(arr[i] + " ");
            }
            System.out.println();
            return;
        }

        for (int i = now; i <= n; i++) {
            arr[cnt] = i;
            func(i + 1, cnt + 1);
        }
    }
}