Engineering Questions with Answers - Multiple Choice Questions

Hash Tables Chaining using Linked Lists Multiple Choice MCQ

1 - Question

The case in which a key other than the desired one is kept at the identified location is called?
a) Hashing
b) Collision
c) Chaining
d) Open addressing

View Answer

Answer: b
Explanation: When some other value is placed at a specified location other than the desired key, it is said to be a collision.




2 - Question

What data organization method is used in hash tables?
a) Stack
b) Array
c) Linked list
d) Queue

View Answer

Answer: c
Explanation: The data structure used to organize data for hash tables is linked list. It contains a data field and a pointer field.




3 - Question

The task of generating alternative indices for a node is called?
a) Collision handling
b) Collision detection
c) Collision recovery
d) Closed hashing

View Answer

Answer: a
Explanation: Collision handling involves the process of formulating alternative indices for a key.




4 - Question

Which of the following is not a collision resolution technique?
a) Separate chaining
b) Linear probing
c) Quadratic probing
d) Hashing

View Answer

Answer: d
Explanation: Hashing is a technique of placing data items in specific locations. Collision may occur in hashing but hashing is not a collision resolution technique.




5 - Question

Hashing is the problem of finding an appropriate mapping of keys into addresses.
a) True
b) False

View Answer

Answer: a
Explanation: Hashing is a data structure which is used to locate data in a table based on a key value.




6 - Question

In a hash table of size 10, where is element 7 placed?
a) 6
b) 7
c) 17
d) 16

View Answer

Answer: b
Explanation: The hash location is defined as hash(f)= key mod table_size.
7 mod 10 gives 7. It is placed in 7th position.




7 - Question

What should be the load factor for separate chaining hashing?
a) 0.5
b) 1
c) 1.5
d) 2

View Answer

Answer: b
Explanation: For hashing using separate chaining method, the load factor should be maintained as 1. For open addressing method, it should not exceed 0.5.




8 - Question

Which of the following operations are done in a hash table?
a) Insert only
b) Search only
c) Insert and search
d) Replace

View Answer

Answer: c
Explanation: Hash tables are used to implement Insert and Find operations in constant average time. This is the prime purpose of hashing.




9 - Question

Which of the following is identical to that of a separate chaining hash node?
a) Linked list
b) Array
c) Stack
d) Queue

View Answer

Answer: a
Explanation: The hash node in separate chaining is similar to that of a linked list. The separate chaining hash table is an array of linked lists.




10 - Question

Which of the following is the hashing function for separate chaining?
a) H(x)=(hash(x)+f(i)) mod table size
b) H(x)=hash(x)+i2 mod table size
c) H(x)=x mod table size
d) H(x)=x mod (table size * 2)

View Answer

Answer: c
Explanation: The hashing function for separate chaining is given by H(x)= key mod table size. H(x)=hash(x)+i2 mod table size defines quadratic probing.




11 - Question

What is the correct notation for a load factor?
a) Ω
b) ∞
c) ∑
d) ⅄

View Answer

Answer: d
Explanation: In general, load factor is denoted as ⅄. In separate chaining method, load factor is maintained as 1.0.




12 - Question

 In hash tables, how many traversal of links does a successful search require?
a) 1+⅄
b) 1+⅄2
c) 1+ (⅄/2)
d) ⅄3

View Answer

Answer: c
Explanation: A successful search requires about 1+ (⅄/2) links to be traversed. There is a guarantee that at least one link must be traversed.




13 - Question

Which of the following is a disadvantage of using separate chaining using linked lists?
a) It requires many pointers
b) It requires linked lists
c) It uses array
d) It does not resolve collision

View Answer

Answer: a
Explanation: One of the major disadvantages of using separate chaining is the requirement of pointers. If the number of elements are more, it requires more pointers.




14 - Question

 What is the worst case search time of a hashing using separate chaining algorithm?
a) O(N log N)
b) O(N)
c) O(N2)
d) O(N3)

View Answer

Answer: b
Explanation: The worst case search time of separate chaining algorithm using linked lists is mathematically found to be O(N).




15 - Question

From the given table, find ‘?’.
Given: hash(x)= x mod 10
hash-tables-chaining-linked-lists-questions-answers-q15
a) 13
b) 16
c) 12
d) 14

View Answer

Answer: c
Explanation: From the given options, 12 mod 10 hashes to 2 and hence ‘?’ = 12.

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