[백준] 10974번 모든 순열 (silver 3

import java.util.Scanner;

public class Main{
    static int n;
    static int[] num;
    static boolean[] visit;
    static StringBuilder sb;
    public static void main(String[] args){
        Scanner input=new Scanner(System.in);
        n=input.nextInt();
        num=new int[n];
        visit=new boolean[n+1];
        sb=new StringBuilder("");
        back(0);
        System.out.println(sb.toString());
    }

    public static void back(int max){
        if(max==n){
            for(int i : num){
                sb.append(i+" ");
            }
            sb.append("\n");
            return;
        }

        for(int i=1; i<=n; i++){
            if(!visit[i]){
                num[max]=i;
                visit[i]=true;
                back(max+1);
                visit[i]=false;
            }

        }
    }

}