Compiler-Design

Question 39

Consider the grammar with the following translation rules and E as the start symbol.

E → E₁ # T     {E.value = E₁.value * T.value}
    |    T     {E.value = T.value}
T → T₁ & F     {T.value = T₁.value + F.value}
    |    F     {T.value = F.value}
F → num        {F.value = num.value}

Compute E.value for the root of the parse tree for the expression: 2 # 3 & 5 # 6 & 4.

A	200
B	180
C	160
D	40

Compiler-DesignGrammarGATE 2004

Question 39 Explanation:

Given expression is
2 # 3 & 5 # 6 & 4
→ Here # means multiplication (*)
& means addition (+)
→ & is having more precedence because it is far from starting symbol, here # and & are left associatives.
2 # 3 & 5 # 6 & 4
⇒ (2 * (3+5)) * (6+4)
⇒ (2 * 8) * (10)
⇒ 16 * 10 = 160

Correct Answer: C

Question 39 Explanation:

Given expression is
2 # 3 & 5 # 6 & 4
→ Here # means multiplication (*)
& means addition (+)
→ & is having more precedence because it is far from starting symbol, here # and & are left associatives.
2 # 3 & 5 # 6 & 4
⇒ (2 * (3+5)) * (6+4)
⇒ (2 * 8) * (10)
⇒ 16 * 10 = 160

Compiler-Design

UGC-NET DEC-2019 Part-2

Compiler-Design

UGC-NET DEC-2019 Part-2

Compiler-Design