You are designing a system to store and retrieve frequently accessed data with high performance. Which of the following hash table collision resolution strategies would generally offer the BEST performance under high load factors?
Linear Probing
Quadratic Probing
Separate Chaining
Double Hashing
In the context of hash tables, what does a high load factor indicate?
A higher probability of collisions.
Lower memory usage.
Faster insertion operations.
A more efficient hash function is being used.
In a hash table with open addressing using linear probing, suppose we perform a sequence of insertions where each key hashes to the same index. What is the time complexity of the nth insertion in the worst case?
O(n)
O(log n)
O(1)
O(n log n)
What security risk arises from storing sensitive data like passwords directly in a hashmap, even when hashed?
Hashmaps are inherently less secure than other data structures for storing passwords.
Storing any data in a hashmap increases the risk of SQL injection attacks.
Hash collisions could allow attackers to bypass authentication.
An attacker gaining access to the hashmap could retrieve the plaintext passwords.
What is a common disadvantage of using a hashmap with a poorly chosen hash function?
Slow key generation
Increased memory usage
Inability to handle duplicate keys
Frequent hash collisions
Which of the following statements accurately describes a key difference in the behavior of Python dictionaries and Java HashMaps?
Python dictionaries maintain insertion order, while Java HashMaps do not guarantee any specific order.
Python dictionaries use separate chaining for collision resolution, while Java HashMaps employ open addressing.
Java HashMaps allow null keys and values, while Python dictionaries do not.
Java HashMaps are synchronized and thread-safe, whereas Python dictionaries are not.
Hopscotch hashing aims to improve the performance of open addressing by:
Limiting the maximum distance a key can be placed from its original hash index.
Employing a binary search tree for efficient collision resolution.
Using multiple hash tables to store keys with different hash values.
Using a dynamic array to resize the table when the load factor gets high.
How does using a cryptographic hash function with a random salt improve the security of a hashmap storing user credentials?
It makes it significantly harder for attackers to perform rainbow table attacks.
It encrypts the data stored in the hashmap, making it unreadable without the decryption key.
It eliminates the possibility of hash collisions.
It prevents unauthorized users from accessing the hashmap's keys.
You are implementing an LRU (Least Recently Used) cache with a fixed capacity. Which data structure combination would be most suitable for efficiently managing the cache?
Binary Search Tree + Heap
Array + Queue
Hashmap + Doubly Linked List
Hashmap + Stack
How can a hash flooding attack impact the performance of a web server using a hashmap to store session data?
It can lead to increased memory usage and faster response times.
It can cause a denial-of-service by forcing the server to handle a large number of collisions.
It can improve the efficiency of the hashmap by distributing data more evenly.
It has no impact on performance, as hash flooding attacks only target data integrity.