코딩테스트 2번

package main2;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

import main.Main;

public class Main2 {

	public  ArrayList<Integer> solution( ArrayList<Integer>arr1,  ArrayList<Integer> arr2){
		
	
		 ArrayList<Integer> answer2 = new ArrayList<Integer>();
		 ArrayList<Integer> answer = new ArrayList<Integer>();
		 
		 answer.addAll(arr1);
		 answer.addAll(arr2);

		 Collections.sort(answer);
	

		 // 0 ~ 9 
		 for(int i = 0; i < answer.size()-1 ; i ++) {
			 
			 if(answer.get(i) == answer.get(i+1))
				 answer2.add(answer.get(i));
		 }
		
		 
	
		return answer2;
	}
	
	
	
	
	
	
	
	
	
	
	
	
	public static void main(String[] args) {
		
		
		 Main2 main2 = new Main2();
		
		 Scanner kb = new Scanner(System.in);
		
		
		 
		 int n=kb.nextInt();
		 
		 ArrayList<Integer> arr1 = new ArrayList<Integer>(); 
		
		 for(int i=0; i<n; i++){
			 
		
			arr1.add(kb.nextInt());
			 
			 
		 };
		 
		 
	     int m=kb.nextInt();
	     ArrayList<Integer> arr2 = new ArrayList<Integer>(); 
	     
	     for(int i=0; i<m; i++){
	    
	    		arr2.add(kb.nextInt());
	    	 
	    	 
	     };
	     
	     
	  
	     
	     for (int x :   main2.solution(arr1,arr2)) {
	    	 System.out.print(x + " ");
	     }
		
	}
	

}