Test: Hashmaps - 1

Question 1

Which of the following best describes a hashmap?

Accepted Answer

A data structure that provides constant-time access to elements based on their keys.

Answer

An ordered collection of key-value pairs.

Answer

A data structure that allows duplicate values.

Answer

A collection of elements sorted in ascending order.

Question 2

What is hashing in the context of hashmaps?

Accepted Answer

A method for converting a key into an array index.

Answer

A technique for sorting elements in a hashmap.

Answer

The process of resizing a hashmap to accommodate more elements.

Answer

The operation of removing an element from a hashmap.

Question 3

Which of the following collision resolution techniques is used in separate chaining?

Accepted Answer

Linked lists

Answer

Linear probing

Answer

Quadratic probing

Answer

Double hashing

Question 4

What is the purpose of open addressing in hashmaps?

Accepted Answer

To find the next available slot when a collision occurs.

Answer

To handle collisions by storing multiple values for the same key.

Answer

To convert a key into an array index.

Answer

To resize the hashmap dynamically.

Question 5

The Rabin-Karp algorithm is primarily used for which of the following?

Accepted Answer

String matching

Answer

Hashing passwords

Answer

Searching in a binary tree

Answer

Sorting arrays

Question 6

What will be the output of the following code?
#include
#include

int main() {
std::unordered_map map;
map[1] = "Alice";
map[2] = "Bob";
map[3] = "Charlie";

std::cout << map[2] << std::endl;
return 0;
}

Accepted Answer

Bob

Answer

Alice

Answer

Charlie

Answer

Compilation error

Question 7

What will be the output of the following code?
#include
#include

int main() {
std::unordered_map map;

for (int i = 0; i < 5; i++) {
map[i] = i * 10;
}

std::cout << map[5] << std::endl;
return 0;
}

Accepted Answer

Garbage value

Answer

0

Answer

10

Answer

40

Question 8

What will be the output of the following code?
#include
#include

int main() {
std::unordered_map map;

map[1] = 10;
map[2] = 20;
map[3] = 30;
map[4] = 40;

std::cout << map.size() << std::endl;
return 0;
}

Accepted Answer

4

Answer

1

Answer

2

Answer

3

Question 9

What will be the output of the following code?
#include
#include

int main() {
std::unordered_map map;

map[1] = 10;
map[2] = 20;
map[3] = 30;
map[4] = 40;

map.erase(2);

std::cout << map.size() << std::endl;
return 0;
}

Accepted Answer

3

Answer

1

Answer

2

Answer

4

Question 10

What will be the output of the following code?
#include
#include

int main() {
std::unordered_map map;

map['a'] = 1;
map['b'] = 2;
map['c'] = 3;
map['d'] = 4;

std::cout << map['z'] << std::endl;
return 0;
}

Accepted Answer

0

Answer

Compilation error

Answer

Runtime error

Answer

Garbage value

Question 11

Which of the following hashing techniques uses the concept of linear probing?

Accepted Answer

Separate chaining

Answer

Quadratic probing

Answer

Double hashing

Answer

Cuckoo hashing

Question 12

Which of the following statements about open addressing is false?

Accepted Answer

Open addressing can handle more elements than separate chaining.

Answer

Open addressing avoids the use of auxiliary data structures for collision resolution.

Answer

Open addressing requires all keys to be stored in the hashmap itself.

Answer

Open addressing can lead to clustering when many collisions occur.

Question 13

The Rabin-Karp algorithm uses which of the following concepts?

Accepted Answer

Rolling hash function

Answer

Quadratic probing

Answer

Separate chaining

Answer

Heap data structure

Question 14

Which of the following collision resolution techniques is used in open addressing?

Accepted Answer

Linear probing

Answer

Linked lists

Answer

Red-black trees

Answer

Hash functions

Question 15

Which of the following is a drawback of using separate chaining for collision resolution?

Accepted Answer

Increased memory usage due to linked lists.

Answer

Inefficient search operation for large hashmaps.

Answer

Difficulty in implementing the hashmap data structure.

Answer

High probability of collisions.

Hashmaps - 1 - Free MCQ Practice Test with solutions, Software Development

MCQ Practice Test & Solutions: Test: Hashmaps - 1 (15 Questions)

Which of the following best describes a hashmap?

What is hashing in the context of hashmaps?

Which of the following collision resolution techniques is used in separate chaining?

What is the purpose of open addressing in hashmaps?

The Rabin-Karp algorithm is primarily used for which of the following?

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, std::string> map;
map[1] = "Alice";
map[2] = "Bob";
map[3] = "Charlie";
std::cout << map[2] << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, int> map;
for (int i = 0; i < 5; i++) {
map[i] = i * 10;
}
std::cout << map[5] << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, int> map;
map[1] = 10;
map[2] = 20;
map[3] = 30;
map[4] = 40;
std::cout << map.size() << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, int> map;
map[1] = 10;
map[2] = 20;
map[3] = 30;
map[4] = 40;
map.erase(2);
std::cout << map.size() << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<char, int> map;
map['a'] = 1;
map['b'] = 2;
map['c'] = 3;
map['d'] = 4;
std::cout << map['z'] << std::endl;
return 0;
}

Which of the following hashing techniques uses the concept of linear probing?

Which of the following statements about open addressing is false?

The Rabin-Karp algorithm uses which of the following concepts?

Which of the following collision resolution techniques is used in open addressing?

Which of the following is a drawback of using separate chaining for collision resolution?

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DSA in C++

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Hashmaps - 1 - Free MCQ Practice Test with solutions, Software Development

MCQ Practice Test & Solutions: Test: Hashmaps - 1 (15 Questions)

Which of the following best describes a hashmap?

What is hashing in the context of hashmaps?

Which of the following collision resolution techniques is used in separate chaining?

What is the purpose of open addressing in hashmaps?

The Rabin-Karp algorithm is primarily used for which of the following?

What will be the output of the following code? #include <iostream> #include <unordered_map>int main() { std::unordered_map<int, std::string> map; map[1] = "Alice"; map[2] = "Bob"; map[3] = "Charlie"; std::cout << map[2] << std::endl; return 0; }

What will be the output of the following code? #include <iostream> #include <unordered_map>int main() { std::unordered_map<int, int> map; for (int i = 0; i < 5; i++) { map[i] = i * 10; } std::cout << map[5] << std::endl; return 0; }

What will be the output of the following code? #include <iostream> #include <unordered_map>int main() { std::unordered_map<int, int> map; map[1] = 10; map[2] = 20; map[3] = 30; map[4] = 40; std::cout << map.size() << std::endl; return 0; }

What will be the output of the following code? #include <iostream> #include <unordered_map>int main() { std::unordered_map<int, int> map; map[1] = 10; map[2] = 20; map[3] = 30; map[4] = 40; map.erase(2); std::cout << map.size() << std::endl; return 0; }

What will be the output of the following code? #include <iostream> #include <unordered_map>int main() { std::unordered_map<char, int> map; map['a'] = 1; map['b'] = 2; map['c'] = 3; map['d'] = 4; std::cout << map['z'] << std::endl; return 0; }

Which of the following hashing techniques uses the concept of linear probing?

Which of the following statements about open addressing is false?

The Rabin-Karp algorithm uses which of the following concepts?

Which of the following collision resolution techniques is used in open addressing?

Which of the following is a drawback of using separate chaining for collision resolution?

DSA in C++

DSA in C++

Top Courses for Software Development

About this Software Development Practice Test

Explore more Software Development Study Resources

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, std::string> map;
map[1] = "Alice";
map[2] = "Bob";
map[3] = "Charlie";
std::cout << map[2] << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, int> map;
for (int i = 0; i < 5; i++) {
map[i] = i * 10;
}
std::cout << map[5] << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, int> map;
map[1] = 10;
map[2] = 20;
map[3] = 30;
map[4] = 40;
std::cout << map.size() << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<int, int> map;
map[1] = 10;
map[2] = 20;
map[3] = 30;
map[4] = 40;
map.erase(2);
std::cout << map.size() << std::endl;
return 0;
}

What will be the output of the following code?
#include <iostream>
#include <unordered_map>
int main() {
std::unordered_map<char, int> map;
map['a'] = 1;
map['b'] = 2;
map['c'] = 3;
map['d'] = 4;
std::cout << map['z'] << std::endl;
return 0;
}