[백준] 15666 : N과 M (12) - JAVA

문제

https://www.acmicpc.net/problem/15666

15666번: N과 M (12)

 

코드

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

class Main {	
	static int n, m;
	static int arr[];
	static int answer [];
	static StringBuilder sb = new StringBuilder();
	
	public static void main(String args[]) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));		
		StringTokenizer st = new StringTokenizer(br.readLine());
		n = Integer.parseInt(st.nextToken());
		m = Integer.parseInt(st.nextToken());
		
		answer = new int [m];
		
		
		HashSet<Integer> set = new HashSet<>();
		
		st = new StringTokenizer(br.readLine());
		for(int i=0;i<n;i++) {
			set.add(Integer.parseInt(st.nextToken()));
		}
		
		arr = new int [set.size()];
		
		Iterator it = set.iterator();
		for(int i=0;i<set.size();i++) {
			arr[i] = (int)it.next();
		}
		
		Arrays.sort(arr);

		
		back(0, 0);
		System.out.print(sb);
		
		
	}

	static public void back(int depth, int start) {
		if(depth == m) {
			for(int i=0;i<m;i++) {
				sb.append(answer[i]+" ");
			}
			sb.append("\n");
			return;
		}
		for(int i=start;i<arr.length;i++) {
			if(depth != 0 && answer[depth-1] > arr[i]) {
				continue;
			}

			answer[depth] = arr[i];
			back(depth+1, i);
			
		}
	}
}