import java.util.Arrays;

public class ArraySet {
    private int capacity;
    private Integer[] array;
    private int size;

    public ArraySet(int capacity) {
        this.capacity = capacity;
        this.array = new Integer[capacity];
        this.size = 0;
    }

    public boolean isEmpty() {
        return size == 0;
    }

    public boolean isFull() {
        return size == capacity;
    }

    @Override
    public String toString() {
        return Arrays.toString(Arrays.copyOf(array, size));
    }

     public boolean contains(Integer e) {  
         for (int i=0;i<size;i++){
             if(array[i].equals(e)){
                 return true;   
             }
         }
         
         // 아래와 같이 한 줄로도 가능
         // return Arrays.asList(array).subList(0, size).contains(e);
         
         return false;   
     }  

     public void insert(Integer e) {  
         if (!contains(e) && !isFull()) {   
             array[size] = e;   
             size++;   
         }  
     }  

     public void delete(Integer e) {  
         for (int i=0;i<size;i++){
            if(array[i].equals(e)){
                array[i]=array[size-1];
                array[size-1]=null;
                size--;
                break;
            }
	}
     }  

     	public ArraySet union(ArraySet setB){
		ArraySet setC=new ArraySet(capacity+setB.capacity);
		
		for(int i=0;i<size;i++){
			setC.insert(array[i]);
		}
		
		for(int i=0;i<setB.size;i++){
			if(!setC.contains(setB.array[i])){
				setC.insert(setB.array[i]);
			}
		}
		
		return setC;
      }


     	public ArraySet intersect(ArraySet setB){
         	ArraySet setC =new ArraySet(capacity);
         	
         	for(int i=0;i<size;i++){
             	if(setB.contains(array[i])){
                 	setC.insert(array[i]);
                }
            }
            return setC;
                
       }


      	public ArraySet difference(ArraySet setB){
          	ArraySet setC= new ArraySet(capacity);
          	
          	for(int i=0;i<size;i++){
              	if(!setB.contains(array[i])){
                  	setC.insert(array[i]);
                }
            }
            return setC;
       }



  	public static void main(String[] args){
      		ArraySet A=new ArraySet(10);
      		ArraySet B=new ArraySet(10);

      		A.insert(1);A.insert(2);A.insert(3);A.insert(4);A.insert(5);
      		B. insert (3 ); B. insert (4 ); B. insert (5 ); B. insert (6 ); B. insert (7 );

      		System.out.println("집합 A: "+A.toString());
      		System.out.println("집합 B: "+ B.toString());

     		System.out.println(" 2 ∈ A: "+A.contains(2));
     		System.out.println(" A ∪ B : "+A.union(B).toString());
     		System.out.println(" A ∩ B : "+A.intersect(B).toString());
     		System.out.println(" A - B : "+A.difference(B).toString());

            System.out.println("집합 A에서 3 삭제");
            A.delete(3);
            System.out.println("집합 A: "+A.toString());

  	   }
}