Question 1 |
Consider the following grammar along with translation rules.
\begin{aligned} &S \rightarrow S_1 \# T & & \{S._{val}=S_{1.val}*T._{val} \} \\ &S \rightarrow T & & \{S._{val}=T._{val} \} \\ &T \rightarrow T_1 \% R & & \{T._{val}=T_{1.val} \div R._{val} \} \\ &T \rightarrow R & & \{T._{val}=R._{val} \} \\ &R \rightarrow id & & \{R._{val}=id._{val} \} \\ \end{aligned}
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
\begin{aligned} &S \rightarrow S_1 \# T & & \{S._{val}=S_{1.val}*T._{val} \} \\ &S \rightarrow T & & \{S._{val}=T._{val} \} \\ &T \rightarrow T_1 \% R & & \{T._{val}=T_{1.val} \div R._{val} \} \\ &T \rightarrow R & & \{T._{val}=R._{val} \} \\ &R \rightarrow id & & \{R._{val}=id._{val} \} \\ \end{aligned}
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
20 | |
65 | |
160 | |
80 |
Question 1 Explanation:
Question 2 |
Consider the augmented grammar with \{+, *, (, ), id \} as the set of terminals.
\begin{aligned}&S' \rightarrow S \\ &S \rightarrow S+R|R \\ &R \rightarrow R*P|P \\ &P \rightarrow (S)|id \end{aligned}
If I_0 is the set of two LR(0) items \{ [S' \rightarrow S.], [S \rightarrow S.+R] \}, then goto(closure(I_0 ),+) contains exactly ______ items.
\begin{aligned}&S' \rightarrow S \\ &S \rightarrow S+R|R \\ &R \rightarrow R*P|P \\ &P \rightarrow (S)|id \end{aligned}
If I_0 is the set of two LR(0) items \{ [S' \rightarrow S.], [S \rightarrow S.+R] \}, then goto(closure(I_0 ),+) contains exactly ______ items.
2 | |
3 | |
4 | |
5 |
Question 2 Explanation:
Question 3 |
Which one of the following statements is TRUE?
The LALR(1) parser for a grammar G cannot have reduce-reduce conflict if the
LR(1) parser for G does not have reduce-reduce conflict.
| |
Symbol table is accessed only during the lexical analysis phase. | |
Data flow analysis is necessary for run-time memory management. | |
LR(1) parsing is sufficient for deterministic context-free languages. |
Question 3 Explanation:
Question 4 |
Consider the following augmented grammar with \{ \#, @, <, >, a, b, c \} as the set of terminals.
\begin{array}{l} S' \rightarrow S \\ S \rightarrow S \# cS \\ S \rightarrow SS \\ S \rightarrow S @ \\ S \rightarrow < S > \\ S \rightarrow a \\ S \rightarrow b \\ S \rightarrow c \end{array}
Let I_0 = \text{CLOSURE}(\{S' \rightarrow \bullet S\}). The number of items in the set \text{GOTO(GOTO}(I_0 \lt ), \lt ) is ___________
\begin{array}{l} S' \rightarrow S \\ S \rightarrow S \# cS \\ S \rightarrow SS \\ S \rightarrow S @ \\ S \rightarrow < S > \\ S \rightarrow a \\ S \rightarrow b \\ S \rightarrow c \end{array}
Let I_0 = \text{CLOSURE}(\{S' \rightarrow \bullet S\}). The number of items in the set \text{GOTO(GOTO}(I_0 \lt ), \lt ) is ___________
6 | |
7 | |
8 | |
9 |
Question 4 Explanation:
Question 5 |
Consider the following C code segment:
a = b + c;
e = a + 1;
d = b + c;
f = d + 1;
g = e + f;
In a compiler, this code segment is represented internally as a directed acyclic graph (DAG). The number of nodes in the DAG is _____________
a = b + c;
e = a + 1;
d = b + c;
f = d + 1;
g = e + f;
In a compiler, this code segment is represented internally as a directed acyclic graph (DAG). The number of nodes in the DAG is _____________
11 | |
6 | |
5 | |
10 |
Question 5 Explanation:
Question 6 |
Consider the following statements.
S1: Every SLR(1) grammar is unambiguous but there are certain unambiguous grammars that are not SLR(1).
S2: For any context-free grammar, there is a parser that takes at most O(n^3) time to parse a string of length n.
Which one of the following options is correct?
S1: Every SLR(1) grammar is unambiguous but there are certain unambiguous grammars that are not SLR(1).
S2: For any context-free grammar, there is a parser that takes at most O(n^3) time to parse a string of length n.
Which one of the following options is correct?
S1 is true and S2 is false | |
S1 is false and S2 is true | |
S1 is true and S2 is true | |
S1 is false and S2 is false |
Question 6 Explanation:
Question 7 |
A grammar is defined as
A \rightarrow B C
B \rightarrow x \mid B x
C \rightarrow B \mid D
D \rightarrow y \mid Ey
E \rightarrow z
The non terminal alphabet of the grammar is
A \rightarrow B C
B \rightarrow x \mid B x
C \rightarrow B \mid D
D \rightarrow y \mid Ey
E \rightarrow z
The non terminal alphabet of the grammar is
\{A, B, C, D, E\} | |
\{B, C, D, E\} | |
\{A, B, C, D, E,x,y,z\} | |
\{x,y,z\} |
Question 7 Explanation:
Question 8 |
A given grammar is called ambiguous if
two or more productions have the same non-terminal on the left hand side | |
a derivation tree has more than one associated sentence | |
there is a sentence with more than one derivation tree corresponding to it | |
brackets are not present in the grammar |
Question 8 Explanation:
Question 9 |
Given the grammar
s \rightarrow T^{*} S \mid T
T \rightarrow U+T \mid U
U \rightarrow a \mid b
Which of the following statements is wrong?
s \rightarrow T^{*} S \mid T
T \rightarrow U+T \mid U
U \rightarrow a \mid b
Which of the following statements is wrong?
Grammar is not ambiguous | |
Priority of + over * is ensured | |
Right to left evaluation of * and + happens | |
None of these |
Question 9 Explanation:
Question 10 |
Consider the following grammar.
S\rightarrow aSB|d
B\rightarrow b
The number of reduction steps taken by a bottom-up parser while accepting the string aaadbbb is___________.
S\rightarrow aSB|d
B\rightarrow b
The number of reduction steps taken by a bottom-up parser while accepting the string aaadbbb is___________.
5 | |
6 | |
7 | |
8 |
Question 10 Explanation:
There are 10 questions to complete.
in question no. 7 there will be b instead of d in production B
S→aSB∣d
B→b
Thank You Ankush Banik,
We have updated the question.
Nice webiste , Good
B option of Q20 is incomplete