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
11. Is it necessary to sort a file before searching a particular item ?
If less work is involved in searching a element than to sort and then extract, then we don not go for sort
If frequent use of the file is required for the purpose of retrieving specific element, it is more efficient to sort the file.
Thus it depends on situation.
12. List out few of the Application of tree data-structure?
The manipulation of Arithmetic expression,
Symbol Table construction,
Syntax analysis.
13. List out few of the applications that make use of Multilinked Structures?
Sparse matrix, Index generation.
14. List out the areas in which data structures are applied extensively?
15. Minimum number of queues needed to implement the priority queue?
Two. One queue is used for actual storing of data and another for storing priorities.
16. Parenthesis is never required in Postfix or Prefix expressions, why?
Parenthesis is not required because the order of the operators in the postfix /prefix expressions determines the actual order of operations in evaluating the expression
17. What actions are performed when a function is called?
What actions are performed when a function is called?
Ans: When a function is called
i) arguments are passed
ii) local variables are allocated and initialized
ii) transferring control to the function
18. What actions are performed when a function returns?
i) Return address is retrieved
ii) Function is data area is freed
iii) Branch is taken to the return address
19. What are the advantages of linked list over array (static data structure)?
The disadvantages of array are
i) unlike linked list it is expensive to insert and delete elements in the array
ii) One can not double or triple the size of array as it occupies block of memory space.
In linked list
i) each element in list contains a field, called a link or pointer which contains the address of the next element
ii) Successive element is need not occupy adjacent space in memory.
20. What are the disadvantages array implementations of linked list?
i) The no of nodes needed can not be predicted when the program is written.
ii) The no of nodes declared must remain allocated throughout its execution