ISRO CS 2016

Question 31

Consider the following statements about the context free grammar G = {S-->SS , S-->ab , S-->ba , S-->^} I. G is ambiguous II. G produces all strings with equal number of a’s and b’s III. G can be accepted by a deterministic PDA. Which combination below expresses all the true statements about ?

• I only
• I and III only
• II and III only
• I, II and III

Question 32

If L and L\' are recursively enumerable then L is,

• Regular
• Context free
• Context Sensitive
• Recursive

Question 33

S → aSa ∣ bSb ∣ a ∣ b The language generated by the above grammar over the alphabet is the set of

• all palindromes
• all odd length palindromes
• strings that begin and end with the same symbol
• all even length palindromes

Question 34

What is the highest type number that can be assigned to the following grammar?

S → Aa
A → Ba
B → abc

• Type 0
• Type 1
• Type 2
• Type 3

Question 35

Access time of the symbolic table will be logarithmic if it is implemented by

• Linear list
• Search tree
• Hash table
• Self organization list

Question 36

Recursive descent parsing is an example of

• Top-down parsers
• Bottom-up parsers
• Predictive parsers
• None of the above

Question 37

A top-down parser generates

• Rightmost Derivation
• Rightmost derivation in reverse
• Leftmost derivation
• Leftmost derivation in reverse

Question 38

Relative mode of addressing is most relevant to writing

• Co-routines
• Position – independent code
• Shareable code
• Interrupt Handlers

Question 39

With single resource, deadlock occurs

• if there are more than two processes competing for that resources
• if there are only two processes competing for that resources
• if there is a single process competing for that resources
• none of these

Question 40

Peephole optimization is form of

• Loop optimization
• Local optimization
• Constant folding
• Data flow analysis