GATE CS 2022: Compiler Design-2 (App update required to attempt this test)

Which one of the following is a top-down parser?

Which of the following sufficient to convert an arbitrary CFG to an LL(1) grammar?

Consider following grammar :

S → S + A | A

A → D – A | D

D → D * B | B

B → num

The number of internal nodes for the parse tree for 5 * 4 + 10 * 6 – 7 – 8 _________

Consider the following 3-address code.

t₁ = a + b

t₂ = c + d

t₃ = t₁ * t₂

t₄ = t₂ + t₂

t₅ = t₄ + t₃

There are 5 temporary variables in above code. What is the minimum number of temporary variables can be used in the equivalent optimized 3-address code of above code?