1
GATE CSE 2007
MCQ (Single Correct Answer)
+1
-0.3
Which one of the following is a top-down parser?
A
Recursive descent parser.
B
Operator precedence parser.
C
An LR(k) parser.
D
An LALR(k) parser.
2
GATE CSE 2007
MCQ (Single Correct Answer)
+2
-0.6

Consider the grammar with non-terminals N = { S, C, S1 }, terminals T = { a, b, i, t, e }, with S as the start symbol, and the following set of rules:

$$\eqalign{ & S \to iCtS{S_1}\,|\,\,a \cr & {S_1} \to eS\,|\,\,\varepsilon \cr & C \to b \cr} $$

The grammar is NOT LL(1) because:

A
it is left recursive
B
it is right recursive
C
it is ambiguous
D
It is not context-free
3
GATE CSE 2007
MCQ (Single Correct Answer)
+2
-0.6
Consider the following two statements:

P: Every regular grammar is LL(1)
Q: Every regular set has a LR(1) grammar

Which of the following is TRUE?
A
Both P and Q are true
B
P is true and Q is false
C
P is false and Q is true
D
Both P and Q are false
4
GATE CSE 2007
MCQ (Single Correct Answer)
+1
-0.3
Consider the following two statements:

i. A hash function (these are often used for computing digital signatures) is an injective function.
ii. encryption technique such as DES performs a permutation on the elements of its input alphabet.

Which one of the following options is valid for the above two statements?
A
Both are false
B
Statement (i) is true and the other is false
C
Statement (ii) is true and the other is false
D
Both are true