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 2025 Set 2
Numerical
+2
-0

Let $\Sigma=\{1,2,3,4\}$ For $x \in \Sigma^*$, let prod $(x)$ be the product of symbols in $x$ modulo 7 . We take $\operatorname{prod}(\varepsilon)=1$, where $\varepsilon$ is the null string.

For example, $\operatorname{prod}(124)=(1 \times 2 \times 4) \bmod 7=1$.

Define $L=\left\{x \in \Sigma^{\star} \mid \operatorname{prod}(x)=2\right\}$.

The number of states in a minimum state DFA for $L$ is _________ (Answer in integer)

Your input ____
2
GATE CSE 2025 Set 1
MCQ (Single Correct Answer)
+2
-0

Consider the following two languages over the alphabet $\{a, b\}$ :

$$\begin{aligned} & L_1=\left\{\alpha \beta \alpha \mid \alpha \in\{a, b\}^{+} \text {AND } \beta \in\{a, b\}^{+}\right\} \\ & L_2=\left\{\alpha \beta \alpha \mid \alpha \in\{a\}^{+} \text {AND } \beta \in\{a, b\}^{+}\right\} \end{aligned}$$

Which ONE of the following statements is CORRECT?

A
Both $L_1$ and $L_2$ are regular languages.
B
$L_1$ is a regular language but $L_2$ is not a regular language.
C
$L_1$ is not a regular language but $L_2$ is a regular language.
D
Neither $L_1$ nor $L_2$ is a regular language.
3
GATE CSE 2025 Set 1
MCQ (More than One Correct Answer)
+2
-0

Consider the following deterministic finite automaton (DFA) defined over the alphabet, $\Sigma=\{a, b\}$. Identify which of the following language(s) is/are accepted by the given DFA.

GATE CSE 2025 Set 1 Theory of Computation - Finite Automata and Regular Language Question 3 English

A
The set of all strings containing an even number of $b$ 's.
B
  The set of all strings containing the pattern bab.
C
The set of all strings ending with the pattern bab.
D
The set of all strings not containing the pattern aba.
4
GATE CSE 2025 Set 1
Numerical
+2
-0

Consider a finite state machine (FSM) with one input $X$ and one output $f$, represented by the given state transition table. The minimum number of states required to realize this FSM is ________ . (Answer in integer)

Present state Next state Output $f$
$X = 0$ $X = 1$ $X = 0$ $X = 1$
A F B 0 0
B D C 0 0
C F E 0 0
D G A 1 0
E D C 0 0
F F B 1 1
G G H 0 1
H G A 1 0

Your input ____
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