Technical interview questions and answers are the foundation of any Data Structure Interview because companies use DSA to test your problem-solving ability, logic building, and coding efficiency. Data Structures such as arrays, linked lists, stacks, queues, trees, and graphs form the backbone of programming, making this topic one of the most important parts of technical rounds. In campus placements and company-specific interviews conducted by TCS, Infosys, Wipro, Cognizant, and Capgemini, these questions decide whether a candidate has strong fundamentals. This guide covers the most important and frequently asked Data Structure interview questions with clear explanations, helping freshers and job seekers understand concepts easily. Preparing these questions improves performance in coding tests, whiteboard interviews, and online assessments.
Computer science professionals should complement their algorithmic knowledge with C language implementation and Java programming techniques
Showing 10 of 108 questions
21. What are the disadvantages of circular list?
i) We can not traverse the list backward
ii) If a pointer to a node is given we cannot delete the node
22. What are the disadvantages of linear list?
i) We cannot reach any of the nodes that precede node (p)
ii) If a list is traversed, the external pointer to the list must be persevered in order to reference the list again
23. What are the disadvantages of representing a stack or queue by a linked list?
i) A node in a linked list (info and next field) occupies more storage than a corresponding element in an array.
ii) Additional time spent in managing the available list.
24. What are the disadvantages of sequential storage?
i) Fixed amount of storage remains allocated to the data structure even if it contains less element.
ii) No more than fixed amount of storage is allocated causing overflow
25. What are the goals of Data Structure?
It must rich enough in structure to reflect the actual relationship of data in real world. The structure should be simple enough for efficient processing of data.
26. What are the issues that hamper the efficiency in sorting a file?
The issues are
i) Length of time required by the programmer in coding a particular sorting program
ii) Amount of machine time necessary for running the particular program
iii)The amount of space necessary for the particular program .
27. What are the major data structures used in the following areas : network data model & Hierarchical data model.
RDBMS - Array (i.e. Array of structures)
Network data model - Graph
Hierarchical data model - Trees
28. What are the notations used in Evaluation of Arithmetic Expressions using prefix and postfix forms?
Polish and Reverse Polish notations.
29. What do you mean by free pool?
Pool is a list consisting of unused memory cells which has its own pointer.
30. What do you mean by garbage collection?
It is a technique in which the operating system periodically collects all the deleted space onto the free storage list.
It takes place when there is minimum amount of space left in storage list or when CPU is ideal.
The alternate method to this is to immediately reinsert the space into free storage list which is time consuming.