esign:

You are required to implement RandomSentenceGenerator classes with the

following methods:

Java$/$C$++$

A constructor that is passed the name of the file containing the

grammar rules.

A method, randomSentence$(),$ to return a random sentence

generated from the grammar.

$($Java$)$ A toString$()$ method to return the grammar rules in a readable format.

$($C$++)$ The overloaded output stream operator $<<$ to display the

grammar rules in a readable format.

$($C$++)$ A destructor to delete any dynamically allocated space used to store the grammar.

You may add methods to your class as needed. You must implement a separate

main program to test your RandomSentenceGenerator class.

Storing the grammar:

Feel free to use any class library ADTs to store and manipulate the various

components of the grammar. In C$++,$ be sure to store the terminals and variables

as strings allocated to appropriate size $($i$.$e$.$ do not store using a large fixed$-$size

buffer$).$ Recall that a hash table is particularly good for doing quick lookups, so

data you often need to search would best be organized in a hash table, although

you may use other appropriate data structures if you choose.

Expanding the grammar:

Once the grammar is loaded up$,$ begin with the production and expand

it to generate a random sentence. Note that the algorithm to traverse the data

structure and print the terminals is extremely recursive.

The grammar will always contain a variable to begin the expansion. It

will not necessarily be the first definition in the file, but it will always be defined

eventually. Your code can assume that the grammar files are syntactically correct

$($i$.$e$.$ have a start definition, have the correct punctuation and format as described

above, don't have some sort of endless recursive cycle in the expansion, etc.$).$

The one error condition you should catch reasonably, and for which you should

throw an exception, is the case where a variable is used but not defined. It is

fine to catch this when expanding the grammar and encountering the undefined

variable rather than attempting to check the consistency of the entire grammar

while reading it$.$

The names of variables should be considered case$-$insensitively,

matches and $,$ for example.

Input:

Your program should take one command line argument, which is the name of the

grammar file to read. An error message should be displayed if the file is not

found.

Output:

Your program should print the grammar rules and three random sentences from

the grammar and exit.