Java 代码

import java.util.Scanner;
public class Main {
    static int n;
    static int[] path = new int[10];
    static boolean[] state = new boolean[10];
    static void dfs(int num){
        if(num>n){
            for (int i = 1; i <= n; i++) {
                if(state[i])
                    System.out.print(path[i] + " ");
            }
            System.out.println();
            return;
        }
        for (int i = 1; i <= n; i++) {
            if(!state[i]){
                state[i] = true;
                path[num] = i;
                dfs(num+1);
                state[i] =false;
            }

        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        n = scanner.nextInt();
        dfs(1);
    }
}