Write this program in C$++$

Lexical analysis is the process of reading in the stream of characters making up the source code of

a program and dividing the input into tokens. In this assignment, you will use regular expressions

and DFAs to implement a lexical analyzer for a subset of C programming language.

Your Task

Your task is to write a program that reads an input text file, and constructs a list of tokens in

that file. Your program may be written in C$,$ C$++,$ Java or any other programming language.

Assuming that the input file contains the following code string:

$2\mathrm{.}1$ Sample Input $($C$++$ code$)$

void main $()$

$\{$

int sum $=0$;

for$($int j$=0$; j $<mtext\; id="EditorElement\_2495499"></mtext><mn\; id="EditorElement\_2495500">1</mn><mn\; id="EditorElement\_2495501">0</mn>$; j$=$j$+1)$

$\{$

sum $=$ sum $+$ j $+10\mathrm{.}43+34$E$4+45\mathrm{.}34$E$-4+$ E$43+\mathrm{.}34$;

$\}$

$\}$

$2\mathrm{.}2$ Sample Output

The output of the program should be similar to the following:

Class : Lexeme

keyword : void

identifient : main

Lexical analysis

Lexical analysis is the process of reading in the stream of characters making up the source code of

a program and dividing the input into tokens. In this assignment, you will use regular expressions

and DFAs to implement a lexical analyzer for a subset of C programming language.

Your Task

Your task is to write a program that reads an input text file, and constructs a list of tokens in

that file. Your program may be written in C$,$ C$++,$ Java or any other programming language.

Assuming that the input file contains the following code string:

$2\mathrm{.}1$ Sample Input $($C$++$ code$)$

void main $()$

$\{$

int sum $=0$;

for$($int j$=0$; j $<mtext\; id="EditorElement\_2496331"></mtext><mn\; id="EditorElement\_2496332">1</mn><mn\; id="EditorElement\_2496333">0</mn>$; j$=$j$+1)$

$\{$

sum $=$ sum $+$ j $+10\mathrm{.}43+34$E$4+45\mathrm{.}34$E$-4+$ E$43+\mathrm{.}34$;

$\}$

$\}$

$2\mathrm{.}2$ Sample Output

The output of the program should be similar to the following:

Class : Lexeme

keyword : void

identifier : main

$($ : $($

$)$ : $)$

$\{$ : $\{$

keyword : int

identifier : sum

$=$ : $=$

num : $0$

; : ;

keyword : for

$($ : $($

keyword : int

identifier : j

$=$ : $=$

num : $0$

; : ;

identifier : j

$$ : $$

num : $10$

; : ;

identifier : j

$=$ : $=$

identifier : j

$+$ : $+$

num : $1$

$)$ : $)$

$\{$ : $\{$

identifier : sum

$=$ : $=$

identifier : sum

$+$ : $+$

identifier : j

$+$ : $+$

num : $10\mathrm{.}43$

$+$ : $+$

num : $34.$E$4$

$+$ : $+$

num : $45\mathrm{.}34$E$-4$

$+$ : $+$

identifier : E$43$

$+$ : $+$

Error : $.$

num : $34$

; : ;

$\}$ : $\}$

$\}$ : $\}$

Valid Tokens

Programs in this language are composed of tokens displayed in table $1$ :

Construction of Deterministic Finite Automata $($DFA$)$ or Transi$-$

tion Diagrams

You can construct single DFA $($also called transition diagram$)$ for recognizing all tokens in this

language by combining individual DFAs for each type of token. For example you can construct

transition diagram for identifiers and numbers and them merge the start states of two diagrams to

create a single transition diagram that recognizes both numbers and identifiers.

For identifying keywords, you can store keywords in some data structure $($hashmap or string

array$).$ Whenever your program recognizes a token of identifier, you can check your map or string

array if this identifier matches any keyword. If it matches any keyword then consider it keyword

otherwise consider it identifier