Why is a good hash function important for hashmap performance?
To allow for efficient resizing of the hash table.
To reduce the memory used by the hash table.
To ensure that keys are evenly distributed across the hash table, reducing collisions.
To minimize the number of comparisons required to find an element.
Which of the following data structures is commonly used to implement a hashmap?
Linked List
Array
Tree
Graph
If you were designing a simple hash function for strings, which operation would likely be a core component?
Finding the length of the string.
Sorting the characters in the string alphabetically.
Reversing the string.
Converting characters to their ASCII codes and performing arithmetic operations.
What is the purpose of a load factor in a hashmap?
To measure the efficiency of the hash function.
To determine when to resize the hashmap.
To store the maximum number of key-value pairs.
To count the number of collisions.
What is the time complexity of inserting a key-value pair into a hashmap in the average case?
O(1)
O(n log n)
O(log n)
O(n)
What is a disadvantage of using hashmaps when the number of elements to be stored is not known in advance?
They are more complex to implement than linked lists.
They are not suitable for storing data in a sorted order.
They might require resizing, which can be an expensive operation.
They are less memory-efficient than arrays for storing a fixed number of elements.
A simple hash function for strings could involve summing the ASCII values of each character in the string. What is a potential drawback of this approach?
It's not reversible, meaning you can't get the original string from the hash.
It can't handle strings of varying lengths.
It can lead to a high number of collisions for anagrams.
It's computationally expensive.
Which of these is NOT a desirable property of a good hash function?
It should distribute keys uniformly across the hash table.
It should minimize collisions as much as possible.
It should be deterministic (same input always yields the same output).
It should be computationally expensive to calculate.
What is a disadvantage of using a hashmap?
Inability to handle collisions.
Slow search speed.
Cannot iterate over elements in a specific order.
Keys must be immutable.
What is a real-world application of hashmaps?
Performing depth-first search in a graph.
Compressing files to reduce storage space.
Sorting a list of numbers in ascending order.
Storing and retrieving data in databases.