This document discusses data structures and provides examples of common linear data structures like arrays, stacks, queues, and linked lists. It explains that data structures can be simple, using primitive types, or compound, combining simple structures. Linear data structures store elements in a linear order and support insertion and deletion at one or both ends. Examples provided include stacks, which use a last-in first-out approach, and linked lists, where each node stores data and a link to the next node. Code is presented for implementing a stack data structure with functions like push, pop, peek and isEmpty.

2. It’s a physical implementation that clearly defines a way of storing, accessing
and manipulating data.
Data Structure

3. Types of D.S.
1. Simple Data Structures are built from primitive data types like integers,
characters, booleans.
e.g. : Arrays & Lists
2. Compound Data Structures are made by combining simple data
structures in different ways.
Linear Data Structures Non Linear Data Structures
i. Tree
ii. Graph
iii. etc.
i. Stack
ii. Queue
iii. Linked List

4. Linear List Arrays
Arrays refer to a named list of a finite number n of same type of elements.
Arrays can be one dimensional, two-dimensional or multi-dimensional.
0 1 2 3 4 5
8 0 1 3 4 2

5. Stacks
Last In First Out
Insertion & Deletion both
takes place at the top.
There’s a special way to store lists where we use LIFO technique.

6. Linked List
As the name suggests, it’s a list like implementation where elements are
linked.
DATA DATA
Stores the value stores the address of next node
12&
120
49&
haus
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N
U
L
L

7. Trees are multilevel data structures having a hierarchical relationship
among its elements.
In a linked list, each node stores data & address of next node.
In a Tree, each node stores data & address(es) of child node(s).
Trees
4
5
2
1
2
1

8. 1. Insertion means adding new data element.
2. Deletion means deleting some data element.
3. Searching means finding(maybe index) of some data.
4. Traversal means walking in all elements.
5. Sorting means arranging elements in some order.
6. Merging means combining similar DS.
Operations on DS DS

9. Stacks
Last In First Out
Insertion & Deletion both
takes place at the top.
There’s a special way to store lists where we use LIFO technique.

10. Stacks
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13
8
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13
8
4
5
S S S S S S S
8
4
5
8
4
5
4
5 5
S S S S

11. Stacks
13
8
4
5
3
13
8
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5
3
13
8
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13
8
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5 5
S S S S S S S S S

12. To implement a stack we need to make its functions.
1. isEmpty(s)
2. Push(s,i)
3. Pop(s)
4. Peek(s)
5. Display(s)
Implementing Stack
‘Ghantu’
‘Mintu’
‘Pintu’
‘Chintu’
We need to maintain top of stack, and make it None when stack is empty.

13. STACK IMPLEMENT CODE