GATE-CS-2007

Question 81

Consider the data given in above question. Least Recently Used (LRU) page replacement policy is a practical approximation to optimal page replacement. For the above reference string, how many more page faults occur with LRU than with the optimal page replacement policy?

• 0
• 1
• 2
• 3

Question 82

Suppose that a robot is placed on the Cartesian plane. At each step it is allowed to move either one unit up or one unit right, i.e., if it is at (i,j) then it can move to either (i+1,j) or (i,j+1). 
How many distinct paths are there for the robot to reach the point (10,10) starting from the initial position (0, 0) 

• C
  

• D
  

• B
  

• A
  

Question 83

Consider the data given in above question.
Suppose that the robot is not allowed to traverse the line segment from (4,4) to (5,4). With this constraint, how many distinct paths are there for the robot to reach (10,10) starting from (0,0)? 

• C
  

• D
  

• B
  

• A
  

Question 84

Suppose the letters a, b, c, d, e, f have probabilities 1/2, 1/4, 1/8, 1/16, 1/32, 1/32 respectively. What is the average length of Huffman codes?

• 3
• 2.1875
• 2.25
• 1.9375

Question 85

Suppose the letters a, b, c, d, e, f have probabilities 1/2, 1/4, 1/8, 1/16, 1/32, 1/32 respectively. Which of the following is the Huffman code for the letter a, b, c, d, e, f?

• 0, 10, 110, 1110, 11110, 11111
• 11, 10, 011, 010, 001, 000
• 11, 10, 01, 001, 0001, 0000
• 110, 100, 010, 000, 001, 111