Question

We are using javaCC notation.This is the full question

Given the following grammar:

• String ::= "A" ( "B" | T | V )+
• T ::= ("X" T ) | "Y"
• V ::= ( "C" | "D" )*

Which of the following strings are correct according to this grammar?

Group of answer choices

A C C D X X Y

X X Y

A B C D

A X

A B C D

A C D C

A B C D X Y

A X X X

A X Y X C D

A B X X Y

B C D

A

B X X Y

Answer 1

According to the given gramer

1.The string must start with "A" and follows "B" or "c" or "D" or "x" or "Y"

2.If we see Grammer T it should have either "X" and again calling T or only "Y".This shows that T always ends with "Y". that is If we have "X" in the string it should have any number of "X" and should ends with Y:
eg:XY,XXY,XXXXXY etx they are correct strings
X,XX,XYX etc which ends with X are incorrect strings.

So by considering the about two points

1. ACCDXXY is a correct string.
3.ABCD is correct string
4.ACDC is correct string.
5.ABCDXY is correct string
8.ABXXY is correct string.
10.A is correct string. There("B"|T|V)+ "+" represents either 0 or n times.

2.XXY is incorrect because of reason 1
6.AXXX is incorrect string because of reason 2
7.AXYXCD is incorrect string because of reason 2
9.BCD is incorrect string because of reason 1
11.BXXY is incorrect string because of reason 1