Skip to content
Related Articles

Related Articles

GATE | GATE-CS-2014-(Set-2) | Question 65
  • Last Updated : 18 Apr, 2014

Consider the grammar defined by the following production rules, with two operators ∗ and +

    S --> T * P 
    T --> U | T * U
    P --> Q + P | Q
    Q --> Id
    U --> Id

Which one of the following is TRUE?

(A) + is left associative, while ∗ is right associative
(B) + is right associative, while ∗ is left associative
(C) Both + and ∗ are right associative
(D) Both + and ∗ are left associative

Answer: (B)

Explanation: From the grammar we can find out associative by looking at grammar.

Let us consider the 2nd production
T -> T * U
T is generating T*U recursively (left recursive) so * is 
left associative.

P -> Q + P
Right recursion so + is right associative.
So option B is correct. 

NOTE: Above is the shortcut trick that can be observed after drawing
few parse trees.
One can also find out correct answer by drawing the parse tree.

Quiz of this Question


My Personal Notes arrow_drop_up
Recommended Articles
Page :