Theory of Computation
Finite Automata and Regular Language
Marks 1Marks 2Marks 5
Push Down Automata and Context Free Language
Marks 1Marks 2
Undecidability
Marks 1Marks 2
Recursively Enumerable Language and Turing Machine
Marks 1Marks 2
1
GATE CSE 2022
MCQ (More than One Correct Answer)
+2
-0

Consider the following languages:

$$\eqalign{ & {L_1} = \{ ww|w \in \{ a,b\} *\} \cr & {L_2} = \{ {a^n}{b^n}{c^m}|m,\,n \ge 0\} \cr & {L_3} = \{ {a^m}{b^n}{c^n}|m,\,n \ge 0\} \cr} $$

Which of the following statements is/are FALSE?

A
L1 is not context-free but L2 and L2 are deterministic context-free.
B
Neither L1 nor L2 is context-free.
C
L2, L3 and L2 $$\cap$$ L3 all are context-free.
D
Neither L1 nor its complement is context-free.
2
GATE CSE 2021 Set 2
MCQ (More than One Correct Answer)
+2
-0

For a string w, we define wR to be the reverse of w. For example, if w = 01101 then wR = 10110.

Which of the following languages is/are context-free?

A
{wxwRxR | w, x ∈ {0, 1}*}
B
{wwRxxR | w, x ∈ {0, 1}*}
C
{wxwR | w, x ∈ {0, 1}*}
D
{wxxRwR | w, x ∈ {0, 1}*}
3
GATE CSE 2021 Set 1
Numerical
+2
-0

In a pushdown automaton P = (Q, âˆ‘, Î“, Î´, q0, F), a transition of the form,

GATE CSE 2021 Set 1 Theory of Computation - Push Down Automata and Context Free Language Question 16 English 1

where p, q âˆˆ Q, a âˆˆ Î£ âˆª {ϵ}, and X, Y âˆˆ Î“ âˆª {ϵ}, represents

(q, Y) âˆˆ Î´(p, a, X).

Consider the following pushdown automaton over the input alphabet âˆ‘ = {a, b} and stack alphabet Î“ = {#, A}.

GATE CSE 2021 Set 1 Theory of Computation - Push Down Automata and Context Free Language Question 16 English 2
The number of strings of length 100 accepted by the above pushdown automaton is ______

Your input ____
4
GATE CSE 2020
MCQ (Single Correct Answer)
+2
-0.67

Consider the following languages.

L1 = {wxyx | w, x, y ∈ (0 + 1)+}

L2 = {xy | x, y ∈ (a + b)*, |x| = |y|, x ≠ y}

Which one of the following is TRUE?

A
L1 is regular and L2 is context-free.
B
L1 is context-free but not regular and L2 is context-free.
C
Neither L1 nor L2 is context-free.
D
L1 is context-free but L2 is not context-free.
GATE CSE Subjects
Theory of Computation
Operating Systems
Algorithms
Digital Logic
Database Management System
Data Structures
Computer Networks
Software Engineering
Compiler Design
Web Technologies
General Aptitude
Discrete Mathematics
Programming Languages
Computer Organization