Bagaimana untuk melaksanakan pilih atur penuh dalam algoritma Java

import java.util.ArrayList;
import java.util.List;
 
public class h718_1 {
 
    static List<List<Integer>> res = new ArrayList<>();
    public static void main(String[] args) {
        int[] arr = {1,2,3};
 
        h718_1 h2 = new h718_1();
        h2.dfs(arr,new ArrayList<>());
        for (List<Integer> re : res) {
            System.out.println(re);
        }
 
    }
 
    public List<List<Integer>> dfs( int[] arr,List<Integer> list){
        List<Integer> temp = new ArrayList<>(list);
        if (arr.length == list.size()){
            res.add(temp);
        }
        for (int i=0;i<arr.length;i++){
            if (temp.contains(arr[i])){
                continue;
            }
            temp.add(arr[i]);
            dfs(arr,temp);
            temp.remove(temp.size()-1);
        }
        return res;
    }
 
}

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
 
public class h718_2 {
    static List<List<Integer>> res = new ArrayList<>();
    public static void main(String[] args) {
 
        int[] arr = {1,2,3};
        h718_2 h3 = new h718_2();
        h3.pailie_swap(0,arr);
 
    }
    public void pailie_swap(int index, int[] arr){
        if (arr.length==index){
            System.out.println(Arrays.toString(arr));
            return;
        }
        for (int i = index;i<arr.length;i++){
            swap(i,index,arr);
            pailie_swap(index+1,arr);
            swap(i,index,arr);
        }
 
    }
 
    public void swap(int i,int j ,int[] arr){
        int temp = arr[j];
        arr[j] = arr[i];
        arr[i] = temp;
 
    }
}