[백준] 15657번 N과 M(8) (silver 3

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

public class Main{

    static int[] num;
    static int[] visit;
    static int n;
    static int m;
    static StringBuilder sb=new StringBuilder();
    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));

        StringTokenizer st=new StringTokenizer(br.readLine());
        n=Integer.valueOf(st.nextToken());
        m=Integer.valueOf(st.nextToken());
        num=new int[n+1];
        visit=new int[m+1];

        st=new StringTokenizer(br.readLine());
        for(int i=1; i<=n; i++){
            num[i]=Integer.valueOf(st.nextToken());
        }
        Arrays.sort(num);
        dfs(1,0);

        bw.write(sb.toString());
        bw.flush();

    }

    public static void dfs(int d, int l){
        if(l==m){
            for(int i=1; i<=m; i++){
                sb.append(visit[i]+" ");
            }
            sb.append("\n");
            return;
        }

        for(int i=d; i<=n; i++){
            visit[l+1]=num[i];
            dfs(i,l+1);
        }

    }



}