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Previous Year Question Paper

AL-601 - Theory of Computation

June 2025•AIML•SEMESTER-6
June 2025
Max Marks: 70
Duration: 3 Hours
Instructions:

• Attempt any five questions.

• All questions carry equal marks.

Q.1
a)Unit 1

Define finite automata and list the features of finite automata with an example.

b)Unit 2

Design a finite automata with Σ={0,1}\Sigma = \{0,1\} accepts those strings which starts with 11 and ends with 00.

Q.2
a)Unit 1

Differentiate between Mealy and Moore machines with a suitable example.

b)Unit 2

Design a regular expression for the following DFA.

States01
→Q1Q2Q1
*Q2Q2Q1
Q.3
a)Unit 2

Consider the following NFA with epsilon: compute the ε\varepsilon-closure of each state; give all the strings of length 4 or less accepted by the automation; convert the automation to DFA.

Statesε\varepsilonABC
→P∅\emptysetPQR
QPQRP
*RQR∅\emptysetP
Q.4
a)Unit 4

Show that the language L={0n1m∣n=m and n≥1}L = \{0^n 1^m \mid n = m \text{ and } n \ge 1\} is deterministic context free language.

b)Unit 3

Define parse tree and construct a parse tree for the string 'abaabb' from the following given grammar: S→SS∣aSb∣εS \to SS \mid aSb \mid \varepsilon.

Q.5
a)Unit 3

Convert the given CFG into GNF: S→ABA∣AAB∣BA∣AA∣BS \to ABA \mid AAB \mid BA \mid AA \mid B; A→aA∣aA \to aA \mid a; B→bB∣bB \to bB \mid b.

b)Unit 4

Define pushdown automata and explain its model with a neat sketch.

Q.6
a)Unit 4

Construct a PDA for the given language L={WWR∣W∈{a,b}∗}L = \{WW^R \mid W \in \{a,b\}^*\}.

b)Unit 4

Convert the following grammar into PDA which accepts the same language by empty stack: S→0S1∣AS \to 0S1 \mid A; A→1A0∣S∣εA \to 1A0 \mid S \mid \varepsilon.

Q.7
a)Unit 5

Design a Turing machine over {0,1} for the language L = {W/W is a multiple of 3}.

b)Unit 5

Find whether the post correspondence problem P = {(ba, bab), (abb, bb), (bab, abb)} has a match? Explain in detail.

Q.8
a)Unit 5

Write a short note on any two of the following: (a) Arden's theorem (b) Chomsky hierarchy of the grammar (c) NPDA (d) N-P Complete problem.