Frequently asked Data Structures Questions:

Below are of some of the very popular data structures question which is asked in various companies hirings. These questions are asked from candidates having 2 to 15 years of experience in the industry.

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1. Reverse a String using Stack
2. Sort a stack using recursion
3. Next Greater Element
4. Implement Stack using Queues
5. Largest Rectangular Area in a Histogram
6. Iterative Postorder Traversal
7. Iterative Preorder Traversal
8. Iterative inorder Traversal
9. Expression evaluation
10. Reverse a linked list
11. Detect and Remove Loop in a Linked List
12. Merge two sorted linked lists
13. Intersection point of two Linked Lists.
14. Pairwise swap elements of a given linked list
15. Merge Sort for Linked Lists
16. Convert a given Binary Tree to Doubly Linked List
17. Merge Sort for Doubly Linked List
18. Implement Queue using Stacks
19. Implement LRU Cache
20. Print Postorder traversal from given Inorder and Preorder traversals
21. Print a Binary Tree in Vertical Order
22. Boundary Traversal of binary tree
23. Root to leaf path sum equal to a given number
24. How to determine if a binary tree is height-balanced?
25. Write a Program to Find the Maximum Depth or Height of a Tree
26. Write Code to Determine if Two Trees are Identical
27. Connect nodes in trees at same level
28. Print Ancestors of a given node in Binary Tree
29. Given a binary tree, print all root-to-leaf paths
30. Vertical Sum in a given Binary Tree
31. Print Left View of a Binary Tree
32. Check if all leaves are at same level
33. Check if a binary tree is subtree of another binary tree
34. Print Right View of a Binary Tree
35. Print all nodes at distance k from a given node
36. Lowest Common Ancestor in a Binary Tree
37. Print Nodes in Top View of Binary Tree
38. Maximum Path Sum in a Binary Tree
39. Diameter of a Binary Tree in O(n)
40. Inorder predecessor and successor for a given key in BST
41. Check if a binary tree is BST or not
42. Lowest Common Ancestor in a Binary Search Tree.
43. Sorted order printing of a given array that represents a BST
44. Inorder Successor in Binary Search Tree
45. Find k-th smallest element in BST
46. Sorted Linked List to Balanced BST
47. Check whether two strings are anagram of each other
48. Print all pairs of anagrams in a given array of strings
49. Longest Palindromic Substring
50. Longest Non-palindromic substring
51. Longest common subsequence
52. Implementation of atoi()
53. Detect Cycle in a Directed Graph
54. Topological Sorting
55. n-Queenís Problem
56. Find the number of islands
57. Largest Sum Contiguous Subarray
58. Longest Increasing Subsequence
59. Maximum Sum Increasing Subsequence
60. Longest Common Substring