GATE CSE 2026 Set 1 | Hashing Question 2 | Data Structures

GATE CSE 2026 Set 1

MCQ (More than One Correct Answer)

-0

Consider a hash table $P[0,1, \ldots, 10]$ that is initially empty. The hash table is maintained using open addressing with linear probing. The hash function used is $h(x)=(x+7) \bmod 11$. Consider the following sequence of insertions performed on $P$ :

$$ 1,13,22,15,11,24 $$

Which of the following positions in the hash table is/are empty after these insertions are performed?

GATE CSE 2023

MCQ (Single Correct Answer)

-0.33

An algorithm has to store several keys generated by an adversary in a hash table. The adversary is malicious who tries to maximize the number of collisions. Let $$k$$ be the number of keys, $$m$$ be the number of slots in the hash table, and $$k > m$$. Which one of the following is the best hashing strategy to counteract the adversary?

Division method, i.e., use the hash function $$h(k)=k$$ mod $$m$$.

Multiplication method, i.e., use the has function $$h(k) = \left\lfloor {m(kA - \left\lfloor {kA} \right\rfloor )} \right\rfloor $$, where $$A$$ is a carefully chosen constant.

Universal hashing method.

If $$k$$ is a prime number, use Division method. Otherwise, use Multiplication method.

GATE CSE 2022

MCQ (Single Correct Answer)

-0.33

Suppose we are given n keys, m has table slots, and two simple uniform hash functions h₁ and h₂. Further suppose our hashing scheme uses h₁ for the odd keys and h₂ for the even keys. What is the expected number of keys in a slot?

$${m \over n}$$

$${n \over m}$$

$${2n \over m}$$

$${n \over 2m}$$

GATE CSE 2020

Numerical

-0

Consider a double hashing scheme in which the primary hash function is
h₁(k)=k mod 23, and the secondary hash function is h₂(k)=1+(k mod 19).
Assume that the table size is 23. Then the address returned by probe 1 in the probe sequence (assume that the probe sequence begins at probe 0) for key value k=90 is _______.

Your input ____