GATE CS 1999

Question 11

System calls are usually invoked by using:

• A software interrupt
• Polling
• An indirect jump
• A privileged instruction

Question 12

A sorting technique is called stable if:

• It takes O(n*log(n)) time

• It maintains the relative order of occurrence of non-distinct elements

• It uses divide and conquer paradigm

• It takes O(n) space

Question 13

Suppose we want to arrange the ii numbers stored in an array such that all negative values occur before all positive ones. Minimum number of exchanges required in the worst case is:

• n-1
• n
• n+1
• None of the above

Question 14

If one uses a straight two-way merge sort algorithm to sort the following elements in ascending order 20, 47, 15, 8, 9, 4, 40, 30, 12, 17 then the order of these elements after the second pass of the algorithm is:

• 8, 9, 15, 20, 47, 4, 12, 17, 30, 40

• 8, 15, 20, 47, 4, 9, 30, 40, 12, 17

• 15, 20, 47, 4, 8, 9, 12, 30, 40, 17

• 4, 8, 9, 15, 20, 47, 12, 17, 30, 40

Question 15

The number of articulation point of the following graph is:

• 0
• 1
• 2
• 3

Question 16

If n is a power of 2, then the minimum number of multiplications needed to compute aⁿ   is:

• log2n
• √n
• n-1
• n

Question 17

Which of the following is the most powerful parsing method?

• LL(1)
• Canonical LR
• SLR
• LALR

Question 18

Consider the join of a relation R with a relation S. If K has m tuples and S has n tuples, then the maximum and minimum sizes of the join respectively are:

• m+n and 0
• mn and 0
• m+n and m-n
• mn and m+n

Question 19

The relational algebra expression equivalent to the following tuple calculus expression

{ t | t ∈ r ∧ (t[A] = 10 ∧ t[B] = 20 }

is

• a
• b
• c
• d

Question 20

Booth\'s coding in 8-bits for the decimal number -57 is:

• 0-100+1000
• 0-100+100-1
• 0-1+100-10+1
• 00-10+100-1