Automata and compiler, Theory of Computation

Assignment Help:

Automata and Compiler

(1) [25 marks] Let N be the last two digits of your student number. Design a finite automaton that accepts the language of strings that end with the last four bits of the binary expansion of N. (1.1) Make a regular expression ? of this language. For example the set of strings that end with 101 is expressed by a regular expression (0+1)*101. (1.2) Make an NFA that accepts this expression ?. You should remove any ?-moves that can be done trivially by inspection. (1.3) Make a subset automaton that accepts the language. (1.4) Perform state minimization on the above automaton.

(2) [25 marks] A CFG is given by S ? aSbS, S ? bSaS, S ? c

(2.1) Draw a syntax chart for this grammar. [5]

(2.2) Write a Python program for the recursive descent parser Trace the parser using two strings of at least 10 symbols, one for an accepted case and one for an unaccepted case. Do the trace using the style in the notes. [20]

(3) [25 marks] A sample program for computing the greatest common divisor by recursive call and its object program are given below. Some sample comments are given.

const a=75, b=55;

var x, y;

procedure gcd;

var w;

begin

if y>0 then begin

w:=y;

y:=x ? (x/y)*y;

x:=w;

call gcd;

end;

end;

begin

x:=a; y:=b;

call gcd;

write(x);

end.

0 jmp 0 21 Jump to 21, start of main

1 jmp 0 2

2 inc 0 4

3 lod 1 4

4 lit 0 0 Load literal 0

5 opr 0 12 Test if y>0

6 jpc 0 20 Jump to 20 if false

7 lod 1 4 Load y

8 sto 0 3 Store in w

9 lod 1 3

10 lod 1 3

11 lod 1 4

12 opr 0 5

13 lod 1 4

14 opr 0 4

15 opr 0 3

16 sto 1 4

17 lod 0 3

18 sto 1 3

19 cal 1 2

20 opr 0 0

21 inc 0 5

22 lit 0 75

23 sto 0 3

24 lit 0 55

25 sto 0 4

26 cal 0 2

27 lod 0 3

28 wrt 0 0 Write stack top

29 opr 0 0


Related Discussions:- Automata and compiler

Non-regular languages, Suppose A = (Q,Σ, T, q 0 , F) is a DFA and that Q = ...

Suppose A = (Q,Σ, T, q 0 , F) is a DFA and that Q = {q 0 , q 1 , . . . , q n-1 } includes n states. Thinking of the automaton in terms of its transition graph, a string x is recogn

Finite-state automaton, Paths leading to regions B, C and E are paths which...

Paths leading to regions B, C and E are paths which have not yet seen aa. Those leading to region B and E end in a, with those leading to E having seen ba and those leading to B no

Construct a recognizer, Let L1 and L2 be CGF. We show that L1 ∩ L2 is CFG t...

Let L1 and L2 be CGF. We show that L1 ∩ L2 is CFG too. Let M1 be a decider for L1 and M2 be a decider for L2 . Consider a 2-tape TM M: "On input x: 1. copy x on the sec

Example of finite state automaton, The initial ID of the automaton given in...

The initial ID of the automaton given in Figure 3, running on input ‘aabbba' is (A, aabbba) The ID after the ?rst three transitions of the computation is (F, bba) The p

Non-determinism - recognizable language, Our DFAs are required to have exac...

Our DFAs are required to have exactly one edge incident from each state for each input symbol so there is a unique next state for every current state and input symbol. Thus, the ne

Kleene closure, One might assume that non-closure under concatenation would...

One might assume that non-closure under concatenation would imply non closure under both Kleene- and positive closure, since the concatenation of a language with itself is included

Theory of computation, Computations are deliberate for processing informati...

Computations are deliberate for processing information. Computability theory was discovered in the 1930s, and extended in the 1950s and 1960s. Its basic ideas have become part of

Notes, write short notes on decidable and solvable problem

write short notes on decidable and solvable problem

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd