exit midterm exam

NAME$\underset{¯}{}$

 
CSE 756: Mid Term Exam
 
Tu, April 29, 1:30—2:48
Open Notes, Open Books
The exam consists of $\underset{¯}{three}$ problems
Answers not appearing in designated spaces WILL NOT be graded

Problem #1 (10 points)

Write a table-driven scanner for the language defined by the following grammar.

1.	<command>	$\to$	<command> <command>
2.		$\to$	DO <parms> $\left\{\right.$ <command> $\left.\right\}$
3.		$\to$	<op> <parms>
4.	<parms>	$\to$	( <integer>,<integer> )
5.	<op>	$\to$	LINE
6.		$\to$	MOVE

Problem #2 (10 points)

Consider the following grammar.

1.	S	$\to$	CA
2.	A	$\to$	aA
3.		$\to$	a
4.	C	$\to$	b
5.		$\to$	$bC$

1. Provide a leftmost and a rightmost derivation for a string in the language
2. Provide a pushdown automaton that simulates the leftmost derivations for the given grammar.
3. Provide a (deterministic) recursive descend program for recognizing the strings in the language

Problem #3 (10 points)

Consider the following grammar.

1.	S	$\to$	a
2.		$\to$	bSC
3.	C	$\to$	cS
4.		$\to$	$ϵ$

1. Use the string ‘b b a c a’ to show that the grammar defines an ambiguous language
2. Show the FIRST(1) and FOLLOW(1) functions for the nonterminal symbols.
3. Construct the LL(1) parse table for $Lx$. Some cells in the table may contain multiple entries.