Consider the CFG with {S,A,B) as the non-terminal alphabet, {a,b) as the terminal alphabet, S as the start symbol and the following set of production rules
S --> aB S --> bA B --> b A --> a B --> bS A --> aS B --> aBB A --> bAA
Which of the following strings is generated by the grammar?
(A) aaaabb
(B) aabbbb
(C) aabbab
(D) abbbba
Answer: (C)
Explanation: Given below production rules.
S --> aB S --> bA B --> b A --> a B --> bS A --> aS B --> aBB A --> bAA
We can derive aabbab using below sequence
S -> aB [Using S --> aB] -> aaBB [Using B --> aBB] -> aabB [Using B --> b] -> aabbS [Using B --> bS] -> aabbaB [Using S --> aB] -> aabbab [Using B --> b]