集合元素去重

import java.util.*;
import java.lang.*;
import java.io.*;

/*
 arr, representing the list of positive integers.
*/
public class Solution
{
    public static int[] removeDuplicate(int[] arr)
    {
        List<Integer> distinctList = new ArrayList<>();
        for (int num : arr) {
            if (!distinctList.contains(num)) {
                distinctList.add(num);
            }
        }
        int[] result = new int[distinctList.size()];
        for (int i = 0; i < distinctList.size(); i++) {
            result[i] = distinctList.get(i);
        }
        return result;
    }

    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
        //input for arr
        int arr_size = in.nextInt();
        int arr[] = new int[arr_size];
        for(int idx = 0; idx < arr_size; idx++)
        {
            arr[idx] = in.nextInt();
        }

        int[] result = removeDuplicate(arr);
        for(int idx = 0; idx < result.length; idx++)
        {
            System.out.print(result[idx] + " ");
        }
    }
}