题解 | #整型数组合并#

import java.util.Scanner;
import java.util.TreeSet;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        TreeSet<Integer> set = new TreeSet<>();
        while (in.hasNextInt()) {
            int a = in.nextInt();
            int[] arr = new int[a];
            for (int i = 0; i < a; i++) {
                arr[i] = in.nextInt();
                set.add(arr[i]);
            }
        }
        for (int a : set) {
            System.out.print(a);
        }
    }
}