You will write a command parser that provides a textual input interface to your program, a circuit database program which contains a number of resistors. We do not implement the database here, just the front-end that accepts commands. The parser should take a sequence of commands as input. Each command consists of an operation followed by its arguments. The command and the arguments are separated by one or more whitespace characters1 The program should take input from the terminal or a file, parse it, verify that it is correct, and print a response or error message. It will loop, processing input according to the specification laid out below as long as input is available.

Your task is to implement a program for storing resistors in a circuit. The network is defined by a number of nodes, each node being connected to one or more resistors.

This lab builds on the previous lab in its use of classes, constructors, and member functions. You will also need to be familiar with dynamic memory allocation using new and delete, the linked list data structure, and destructors.

You will implement three classes: DBentry, TreeNode and TreeDB. The DBentry class will be used to create objects that hold an entry of the database. Each entry has a key (a string, corresponding to the name of the internet domain) and some data (a 32-bit integer that gives the IP address and a boolean flag that indicates whether the computer at that IP address is active or not).

In this lab you will gain experience with inheritance and virtual functions, which are powerful aspects of C++ that allow new types of code re-use. You will do this by enhancing a program that can store, manipulate, and draw a database of shapes.