백준 15649 : N과 M (1) _자바 Java

https://www.acmicpc.net/problem/15649

15649번: N과 M (1)

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

public class Main {
	
	public static int[] arr;
	public static boolean[] visit;
	
	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String str= br.readLine();
		StringTokenizer st = new StringTokenizer(str," ");
		int N = Integer.parseInt(st.nextToken());	//1부터 n까지
		int M = Integer.parseInt(st.nextToken());	//길이가 m개인 수열 
		
		arr = new int[M];
		visit = new boolean[N];
		bt(N,M,0);
		
	}
	private static void bt(int N,int M,int depth) {

		if (depth == M) {
			for (int val : arr) {
				System.out.print(val + " ");
			}
			System.out.println("");
			return;
		}
 
		for (int i = 0; i < N; i++) {
			if (!visit[i]) {
				visit[i] = true;
				arr[depth] = i + 1;
				bt(N, M, depth + 1);
				visit[i] = false;
			}
		}
				
	}
	
}