/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    private static List<List<Integer>> lists = new ArrayList<>();
 
    static List<List<Integer>> permute(List<Integer> arr, int k) {
        for (int i = k; i < arr.size(); i++) {
            Collections.swap(arr, i, k);
            permute(arr, k + 1);
            Collections.swap(arr, k, i);
        }
        if (k == arr.size() - 1) {
            lists.add(arr);
        }
        return lists;
    }
 
    static List<List<Integer>> permute(List<Integer> arr) {
        return permute(arr, 0);
    }
 
    public static void main(String[] args) {
        System.out.println(permute(Arrays.asList(1, 2, 3)));
    }
}

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