#include <iostream>
#include <string>
using namespace std;
typedef const char * String;
#define MAX_CHILDREN	10

class Component{
public:
 	String name;
 	Component(String name):name(name){ }
    virtual void Add(Component *c)=0;
    virtual void Remove(Component *c)=0;
    virtual void Display(int depth)=0;
    virtual ~Component(){
    	//cout<<"Calling ~Component()"<<endl;
    	//Delete any dynamic data here...
	}
};

class Composite:public Component{
	Component *children[MAX_CHILDREN];
public:
 	Composite(String name):Component(name){
		for(int i=0;i<MAX_CHILDREN;i++) children[i] = 0;
	}
	~Composite(){
		//cout<<name<<" is destroyed.."<<endl;
		for(int i=0;i<MAX_CHILDREN;i++) delete children[i];
	}
    void Add(Component *component){
      for(int i=0;i<MAX_CHILDREN;i++){
    	if (!children[i]){
    		children[i] = component;
    		break;
		}
	  }
    }
    void Remove(Component *component){
    	Component **pc;
    	pc = children;
    	for(int i=0;i<MAX_CHILDREN;i++){
    		if (pc[i]==component){
    			for(int j=i;j<(MAX_CHILDREN-1);j++){
    				pc[j] = pc[j+1];
				}
				pc[MAX_CHILDREN-1] = 0;
				break;    			
			}
		}
    }
    void Display(int depth){
      for(int i=0;i<depth;i++) cout<<'-';
      cout<<name<<endl;
      for(int i=0;i<MAX_CHILDREN;i++) {
      	if(children[i]) children[i]->Display(depth+2);
	  }
    }
};

class Leaf:public Component{
public:
	Leaf(String name):Component(name){}

    void Add(Component *c){
      //cout<<"Cannot add to a leaf"<<endl;
    }

    void Remove(Component *c){
      //cout<<"Cannot remove from a leaf"<<endl;
    }

    void Display(int depth){
      for(int i=0;i<depth;i++) cout<<'-';
      cout<<name<<endl;
    }
    ~Leaf(){
		//cout<<name<<" is destroyed.."<<endl;
	}
};
  
main(){
    // Create a tree structure 
    Component *root = new Composite("root");
    root->Add(new Leaf("Leaf A"));
    root->Add(new Leaf("Leaf B"));

    Composite *comp = new Composite("Composite X");
    comp->Add(new Leaf("Leaf XA"));
    comp->Add(new Leaf("Leaf XB"));

    root->Add(comp);
    root->Add(new Leaf("Leaf C"));

    //Add and remove a leaf 
    Leaf *leaf = new Leaf("Leaf D");
    root->Add(leaf);
    root->Remove(leaf);
    delete leaf;

    //Recursively display tree 
    root->Display(1);
    delete root;
    return 0;
}

/*=================== OUTPUT ===================
-root
---Leaf A
---Leaf B
---Composite X
-----Leaf XA
-----Leaf XB
---Leaf C
=================================================*/