class Chain...{
    Chain pre=null,next=null;
    int id;
    String name;
}

class List...{
    private Chain header=new Chain();
    
    public Chain add(int id,String name)...{ //在链表尾添加节点
        Chain current=new Chain(); //创建链表头
        Chain temp=header;
    
        while(temp.next!=null) //循环至链表尾
            temp=temp.next;
        temp.next=current;
        current.pre=temp;    
        current.id=id;
        current.name=name;
        return current;
    }
    
    public Chain remove(int id)...{ //删除指定id的节点
        Chain temp=header;
        Chain current=null;
        while(temp.next!=null)...{
            temp=temp.next;
            if(temp.id==id)...{
                current=temp;
                break;
            }
        }
        if(current==null)
            return null;        
        
        current.pre.next=current.next;
        if(current.next!=null)
            current.next.pre=current.pre;
        return current;
    }
    
    public Chain remove(String name)...{ //删除指定name的节点
        Chain temp=header;
        Chain current=null;
        while(temp.next!=null)...{
            temp=temp.next;
            if(temp.name==name)...{
                current=temp;
                break;
            }
        }
        if(current==null)
            return null;
        
        current.pre.next=current.next;
        if(current.next!=null)
            current.next.pre=current.pre;
        return current;
    }    

    public Chain remove()...{ //删除最后一个节点
        Chain temp=header;
        while(temp.next.next!=null)...{
            temp=temp.next;
        }
        temp.next=null;    
        return temp;
    }
    
    public void clear()...{ //删除所有节点
        header.next=null;
    }
    
    public Chain insert(int id,String name,int pos)...{ //在指定位置插入节点
        Chain temp=header;
        Chain current=new Chain();
        int i=0;
        
        for(i=0;i<=pos;i++)...{
            if(temp.next!=null)...{
                temp=temp.next;
            }
            else...{
                return null;
            }        
        }
        
        current.id=id;
        current.name=name;
        
        if(temp.next!=null)...{
            temp.next.pre=current;
            current.next=temp.next;
        }
        temp.next=current;
        current.pre=temp;
        return current;    
    }
    
    public void print_all()...{
        Chain temp=header;
        
        System.out.println("--------------------------------------");
        while(temp.next!=null)...{
            temp=temp.next;
            System.out.println("ID: "+temp.id);
            System.out.println("Name: "+temp.name);
        }
        System.out.println("--------------------------------------");
    }
}