int数组的全排列

import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int arr[] = new int[n];
        for(int i=0;i<n;i++){
            arr[i] = sc.nextInt();
        }
        sc.close();
       Permutation(arr,0); 
    }
    public static void Permutation(int arr[],int start){
        if(start == arr.length-1){
            Print(arr);
        }
        for(int i=start;i<=arr.length-1;i++){
            if(i==start||arr[i]!=arr[start]){
                Swap(arr,i,start);
                Permutation(arr, start+1);
                Swap(arr,i,start);
            }
        }
    }
    public static void Swap(int arr[],int i,int j){
        int temp;
        temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
    public static void Print(int arr []){
        for(int i=0;i<arr.length-1;i++)
           System.out.print(arr[i]+ " ");
        System.out.println(arr[arr.length-1]);   
    }
}