DataStructure Interview Q's Flashcards
What is an array?
An array is a data structure consisting of a collection of elements, each identified by at least one array index or key.
Can an array be resized at runtime?
In some programming languages, arrays can be resized dynamically, while in others, such as C, the size is fixed.
What is the time complexity for accessing an element in an array?
The time complexity for accessing an element in an array is O(1), as it can be accessed directly using its index.
What is the difference between an array and a linked list?
An array is a static data structure, while a linked list is a dynamic data structure. Arrays have a fixed size, and elements are stored consecutively in memory, while linked lists can grow and do not require contiguous memory allocation.
How would you find the smallest and largest element in an array?
To find the smallest and largest elements in an array, one common approach is to iterate through the array and keep track of the smallest and largest elements encountered so far.
Explain the concept of a multi-dimensional array.
A multi-dimensional array is an array that contains other arrays. For example, a 2D array is an array of arrays, representing a matrix.
How would you reverse an array in-place in linear time and constant space?
One approach is to use two pointers starting from the beginning and end of the array and swap the elements until they meet in the middle.
How can you find duplicate elements in an array?
One way to find duplicate elements in an array is to use a hash set or to sort the array and then iterate through it to find consecutive duplicates.
Discuss the advantages and disadvantages of using arrays.
Advantages: Constant time access, simple implementation, and efficient storage for contiguous data.
Disadvantages: Fixed size, no support for dynamic growth, inefficient for insertions and deletions.
What is a hash data structure?
A hash data structure is a data structure that stores key-value pairs, where the keys are hashed to determine the location of the value in the data structure.
What is a hash table?
A hash table is a data structure that implements an associative array, allowing fast retrieval of values based on unique keys. It uses a hash function to map keys to indices in an array, providing constant-time average access (O(1)) if collisions are minimized.
What is a hash function?
A hash function is a function that takes an input of any size and produces an output of a fixed size. The output is called a hash value or hash code.
What are the advantages of using a hash data structure?
Hash data structures offer fast lookup, insertion, and deletion operations. They are also space-efficient and can handle large datasets.
What are the disadvantages of using a hash data structure?
Hash data structures can suffer from collisions, which can slow down lookup operations. They also require a hash function that is both efficient and effective.
What is a Data Structure?
The Data Structure is the way data is organized (stored) and manipulated for retrieval and access. It also defines the way different sets of data relate to one another, establishing relationships and forming algorithms.
