SDT(Syntax-Directed Translation) PYQ QUIZ GATE CS

Consider two binary operators '

' and '

' with the precedence of operator

being lower than that of the

operator. Operator

is right associative while operator

is left associative. Which one of the following represents the parse tree for expression (7

3 ­

4 ­

3

2)?

S -> aSa|bSb|a|b; The language generated by the above grammar over the alphabet {a,b} is the set of

Which of the following statements are TRUE?

I.  There exist parsing algorithms for some programming languages 
     whose complexities are less than O(n3).
II.  A programming language which allows recursion can be implemented 
    with static storage allocation.
III. No L-attributed definition can be evaluated in The framework 
     of bottom-up parsing.
IV. Code improving transformations can be performed at both source 
    language and intermediate code level.

Consider the CFG with {S,A,B) as the non-terminal alphabet, {a,b) as the terminal alphabet, S as the start symbol and the following set of production rules

S --> aB        S --> bA
B --> b         A --> a
B --> bS        A --> aS
B --> aBB       A --> bAA

Which of the following strings is generated by the grammar?

A student wrote two context-free grammars G1 and G2 for generating a single C-like array declaration. The dimension of the array is at least one. For example,

int a[10][3]; 

The grammars use D as the start symbol, and use six terminal symbols int ; id [ ] num.

Grammar G1
D → int L;
L → id [E
E → num]
E → num] [E

Grammar G2
D → int L;
L → id E
E → E[num]
E → [num] 

Which of the grammars correctly generate the declaration mentioned above?

Consider the following expression grammar G.

E -> E - T | T
T -> T + F | F
F -> (E) | id

Which of the following grammars are not left recursive, but equivalent to G.

A)
E -> E - T | T
T -> T + F | F
F -> (E) | id

B)
E -> TE'
E' -> -TE' | ε
T -> T + F | F
F -> (E) | id

C)
E -> TX
X -> -TX | ε
T -> FY
Y -> +FY | ε
F -> (E) | id

D)
E -> TX | (TX)
X -> -TX | +TX | ε
T -> id

Consider the following grammar and the semantic actions to support the inherited type declaration attributes. Let X₁, X₂, X₃, X₄, X₅ and X₆ be the placeholders for the non-terminals D, T, L or L₁ in the following table:

Which one of the following are the appropriate choices for X₁, X₂, X₃ and X₄?

Consider the following grammar along with translation rules

Here # and % are operators and id is a token that represents an integer and id. val represents the corresponding integer value. The set of non-terminals is {S, T, R, P} and a subscripted non-terminal indicates an instance of the non-terminal. Using this translation scheme, the computed value of S.val for root of the parse tree for the expression 20#10%5#8%2%2 is _____________. 

Consider the translation scheme shown below

S → T R
R → + T {print ('+');} R | ε
T → num {print (num.val);} 

Here num is a token that represents an integer and num.val represents the corresponding integer value. For an input string '9 + 5 + 2', this translation scheme will print

In a bottom-up evaluation of a syntax directed definition, inherited attributes can