DesignPattern_Structural_Composite

void Main()
{
    Component root = new Composite();
    Component nodeA = new Composite();
    Component nodeB = new Composite();
    root.Add(nodeA);
    root.Add(nodeB);
    root.Show(1);
}

abstract class Component{
    public virtual void Show(int level){}
    public abstract void Add(Component c);
    public abstract void Remove(Component c);
}
class Composite:Component{
    List<Component> components = new List<Component>();
    public override void Add(Component c){components.Add(c);}
    public override void Remove(Component c){components.Remove(c);}
    public override void Show(int level){
        base.Show(level);
        foreach (var component in components)
        {
            component.Show(level+1);
        }
    }
}
class Leaf:Component{
    public override void Add(Component c){throw new NotImplementedException();}
    public override void Remove(Component c){throw new NotImplementedException();}
}