Data Structure Interview Questions
1)What is Data Structure?
2)What are the types of Data Structures?
3) What are the Applications of Data Structure?
4) What is a Stack?
5)What are the Applications of Stack?
6) Give
a real-life example of Stack?
16)Difference between Tree and Binary Tree?
19)What is Height in a Tree?
1)What is Data Structure?
a) Data Structure is the way of collecting and organizing the data in
such a way that
we can perform various kinds of operations on these data in an effective way. b)Some examples of Data Structures are arrays, Linked List,Stack,Queue,etc.. |
2)What are the types of Data Structures?
Data Structures are mainly classified into two types:
a)Linear Data Structure i) A Data Structure is called linear if all of its elements are arranged in the sequential order. ii) In linear Data Structures, the elements are stored in a non-hierarchical way where each item has the successors and predecessors except the first and last element. b) Non-Linear Data Structure i) The Non-Linear Data Structure does not form a sequence. ii) That is each item (or) element is connected with two (or) more other items in a non-linear arrangement. The data elements are not arranged in the sequential structure. |
a)Compiler Design
b)Operating System c)Database Management System d)Numerical Analysis e)Graphics f)Artificial Intelligence |
a)The stack is one of the data structure (or) stack is a container of objects
that are
inserted and removed according to the
LAST IN FIRST OUT principle.
b)A stack or LIFO (last in, first out) is an abstract data type that serves as a
Collection of elements, with two principal operations:
i) Push, which adds an element to the collection ii) Pop, which removes the last element that was added. iii) In stack, both the operations of push and pop takes place at the same
end that is top of the stack. It can be
implemented by using both
array and linked list.
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a)
The stack is used by compilers to check for balancing of parenthesis, brackets, and braces.
b)
The stack is used to convert an infix expression into a postfix/prefix form.
c) We
can always remove recursion with the help of stacks.
d) Stacks are used for Maintaining function calls.
e) To
implement back functionality in web browsers.
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A good real-life example of a stack is the pile of dinner
plates that you encounter when
you eat at the local cafeteria: When you remove a plate from the pile, you take the plate on the top of the pile. But this is exactly the plate that was added ("inserted'') most recently to the pile by the dishwasher. |
7)What is the Queue?
a) A queue is another special kind of data structure, where items are inserted at one end called the rear, and deleted at the other end called the front. Another name for a
queue
is a FIFO (Or) First-in-First-Out.
b) The operations for a queue are
given below :
Enqueue: which inserts an element at
the end of the queue
Dequeue:
which deletes an element at the end of the queue
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8)What are the Applications of Queue?
a) It is used to schedule the jobs to be processed by the CPU.
b) When multiple users send print
jobs to a printer, each printing job
is kept in
The printing queue. Then the printer prints those jobs according to
FIFO basis.
c) The breadth-first search uses a queue data structure to find an element from a graph.
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9)What is Linked List?
a) Linked List is a very
commonly used linear data structure which consists of
group of nodes in a sequence.
b) Each node holds its own data and the address of the
next node hence forming
a chain-like structure. |
10)What
are Advantages of Linked Lists?
a) Linked Lists are dynamic data structures. They can grow (or)
shrink during the execution of a program
b) Linked Lists have efficient memory Utilization.
c)Linked Lists provide flexibility in inserting a data item at a
specified position and Deletion of the data item from the given position
d) Many Complex applications can be easily carried out with
linked lists.
e) Linked Lists are used to create graphs and trees.
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11)What are the Disadvantages of Linked Lists?
a) It consumes more space because every node requires an
an additional pointer to store
address of the next
node.
b)Searching a particular element in the list is difficult and time-consuming
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12)What
are Applications of Linked Lists?
a) Linked Lists are used to represent and manipulate polynomial.
b) Linked Lists are to implement stack, queue, trees, and graphs.
c) Implement the symbol table in compiler construction.
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13)Comparison between Array and Linked List?
ARRAY
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LINKED LIST
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Size of an array is fixed
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Size of a list is not fixed
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Memory is allocated from the stack
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Memory is allocated from the heap
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It is necessary to specify the number of elements during the declaration
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It is not necessary to specify the number
of elements during declaration |
It occupies less memory than a linked list for the same number of
elements
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It occupies more memory
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14)What is Tree?
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a) The tree is a non-linear data structure.
b) It is a hierarchical collection of nodes.
c) One of the nodes, known as the root,
is at the top of the hierarchy.
d) Each node can have at most one link coming into it.
e) The node where the link originates is called the parent node.
f) The root node has no parent.
g) The links leaving a node point to child nodes.
h) Trees are recursive structures.
i) Each child node is itself the root
of a subtree.
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15)What is Binary Tree?
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a) A binary tree is a tree data
structure in which each node has at most two children,
which are referred to as the left child and the right child. It is implemented mainly using Links.
b)In a binary tree a node
should contain minimum zero sub-nodes maximum of two sub-nodes
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16)Difference between Tree and Binary Tree?
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TREE
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BINARY TREE
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Each element in a tree can have any number
of subtrees.
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Each element in a binary tree has at most
two subtrees.
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The Subtrees in a tree are unordered.
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The Subtrees of each element in a binary
a tree is ordered.
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17)What is the Leaf node in a Tree?
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A node with no children is called leaf nodes. A node which is not a leaf is called an internal
Node.
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18)What is Level in a Tree?
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The level of the node refers to its distance from the root. The maximum number of nodes at any level is 2^n.
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19)What is Height in a Tree?
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The maximum level in a tree determines its height. The height of a node in a tree is the length of the longest path from the node to a leaf.
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20)What is Depth in a Tree?
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The depth of a node is the number of
nodes along the path from the root to that node.
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21)What are the properties of binary trees?
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a)Height of the tree is taken as lower to upper
b)Depth of tree is taken as upper to lower
c)Height of tree=depth of tree=Level - 1
d)Maximum no of nodes at level (L)=2^(L)-1
e)Maximum no of nodes in a binary tree=2^(h+1) -1
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22)What are the ways to Traverse a Binary Tree?
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A Tree Traversal is a method of visiting every node in the tree. By visit, we mean that some types of operation are performed.
There are mainly three common ways to traverse a binary tree
a)Inorder - L P R
b)Preorder - P L R
c)Post order - L R P
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23)Tell Some Applications of Tree Data Structure?
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a) The file system on a computer.
b) Used in Compilers.
c) Manipulation of Arithmetic Expression
d) Used to implement indexing in databases.
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