The document provides an overview of the stack data structure, emphasizing its last in, first out (LIFO) principle and key operations such as push, pop, and peek, all of which have constant time complexity. It discusses array-based and linked list-based implementations, common use cases like arithmetic expression evaluation and function calls, as well as the advantages and disadvantages of using stacks. Overall, it highlights the simplicity and efficiency of stacks while noting their limitations regarding element access and fixed sizes in some implementations.

1. Name: Sampad Kar
Student Code: BWU/BTA/22/225
Course Name: Data Structure And
Algorithms
Course Code: BSCM302
Group: D
Session: 2023-24

2. Understanding
the Stack Data
Structure

3. Contents
• What is Stack
• Key Operations On a
Stack
• Visualization
• Common Use Cases
• Implementations and
Variations
• Advantages and
Disadvantages
• Examples in
Programming

4. What is Stack?
Definition:
A stack is a fundamental linear data
structure that follows the Last In, First
Out (LIFO) principle or First In, Last Out
(FILO) Principle.
It means that the last element added to
the stack is the first one to be removed.
Visual Representation:
Imagine a stack of books on a table. We
add books to the top of the stack and
remove them from the same top
position.

5. Push Operation:
Description: Adds an element to the top
of the stack.
Time Complexity: O(1) - constant time
complexity.
Pop Operation:
Description: Removes the top element
from the stack.
Time Complexity: O(1) - constant time
complexity.
Peek Operation:
Key Operations On a Stack

6. Display Operation:
Description: Prints or displays the contents
of the stack.
Time Complexity: O(n) - linear time
complexity, where n is the number of
elements in the stack.
IsEmpty Operation:
Checks if the stack is empty.
IsFull Operation:
Checks if the stack is full.
Key Operations On a Stack

7. Visualization

8. Implementations and Variations
Array-Based Implementation:
Description: Stacks can be implemented using arrays.
Elements are added or removed from the end of the array,
representing the top of the stack.
Linked List-Based Implementation:
Description: Stacks can also be implemented using linked
lists. Each node in the linked list represents an element in
the stack.

9. Examples in Programming

10. Examples in Programming

11. Examples in Programming

12. Applications
The following are the applications of stacks
• Evaluating arithmetic expressions
1. Infix To Prefix
2. Infix To Postfix
• Balancing the parenthesis
• Towers of Hanoi
• Function calls
• Tree traversal

13. Advantages and Disadvantages
Advantages:
• Stacks are simple and intuitive data structures, making them easy to
understand and implement.
• Key operations such as push, pop, and peek have constant time
complexity (O(1)).
Disadvantages:
• Stacks do not support direct access to elements in the middle.
Access is limited to the top element.
• Some stack implementations have fixed-size constraints, limiting the
number of elements that can be stored.