DSA Practice Questions
Topics Covered:
Data Structures & Algorithms – Arrays, Linked Lists, Trees, Graphs, Sorting, Searching, Greedy, DP, and more
30 Questions
Practice Questions
1. What is the time complexity of accessing an element in an array by index?
2. What is the worst-case time complexity of linear search in an unsorted array?
3. What is the worst-case time complexity of binary search in a sorted array?
4. Which data structure follows the Last-In, First-Out (LIFO) principle?
5. Which data structure is typically used for breadth-first search in a graph?
6. What is the worst-case time complexity of quicksort (without randomized pivot selection)?
7. What is the average-case time complexity of merge sort?
8. Which data structure is most efficiently used to implement a priority queue?
9. What is the worst-case time complexity for inserting an element into a balanced binary search tree (e.g., AVL or Red-Black Tree)?
10. Which data structure offers constant average-time complexity for search, insertion, and deletion?
11. What is the space complexity of a recursive algorithm that uses O(n) stack space?
12. Which algorithm design paradigm involves breaking a problem into subproblems, solving them independently, and then combining their results?
13. Which algorithm is a classic example of a greedy strategy for data compression?
14. What is the main difference between a singly linked list and a doubly linked list?
15. Which graph traversal algorithm uses a stack (either explicitly or via recursion)?
16. What is the time complexity of finding the maximum element in an unsorted array?
17. What is the key property of a binary heap?
18. Which technique involves storing the results of expensive function calls for reuse?
19. Which sorting algorithm is known for its simplicity and has a worst-case time complexity of O(n²)?
20. What is the worst-case time complexity of heap sort?
21. Which data structure is commonly used to represent a sparse matrix efficiently?
22. Which algorithm finds the shortest path in a weighted graph with non-negative weights?
23. What is the time complexity of Kruskal's algorithm for finding a minimum spanning tree?
24. Which data structure is commonly used to implement undo functionality in applications?
25. What is an advantage of using a trie (prefix tree) for string storage?
26. Which algorithmic technique is used to solve problems that exhibit overlapping subproblems and optimal substructure?
27. What is the worst-case time complexity of searching in a balanced binary search tree?
28. Which algorithm can be used for cycle detection in a directed graph?
29. What is the space complexity of merge sort?
30. Which algorithmic technique is typically used to solve the 0/1 knapsack problem?
