Data Structures Explained: Stack, Queue,
Linked List, Trees
Introduction
Data structures are fundamental concepts in computer science. They define how
data is organized, stored, and accessed efficiently in a program. Choosing the
right data structure can significantly improve the performance and readability of
software systems.
Programs constantly process large amounts of data. Without proper structure,
managing this data would be extremely difficult. Data structures help
programmers store information in ways that make operations such as searching,
inserting, deleting, and updating data efficient.
This guide introduces some of the most important data structures used in
programming:
• Stack
• Queue
• Linked List
• Trees
Each structure is explained with diagrams and Python examples.
Basics of Data Structures
A data structure is a method of organizing and storing data so that it can be
accessed and modified efficiently.
Data structures can be broadly classified into two categories:
1. Linear Data Structures
In linear structures, elements are arranged sequentially.
Examples include:
, • Arrays
• Stacks
• Queues
• Linked Lists
2. Non-Linear Data Structures
In non-linear structures, elements are arranged hierarchically.
Examples include:
• Trees
• Graphs
Understanding these structures helps programmers design efficient algorithms
and solve complex computational problems.
Stack
What is a Stack?
A stack is a linear data structure that follows the LIFO principle (Last In,
First Out).
This means the last element added to the stack is the first one removed.
Example in real life:
A stack of plates in a cafeteria. The last plate placed on the stack is the first one
removed.
Stack Operations
A stack mainly supports two operations:
• Push – adds an element to the stack
• Pop – removes the top element from the stack
Other common operations:
Linked List, Trees
Introduction
Data structures are fundamental concepts in computer science. They define how
data is organized, stored, and accessed efficiently in a program. Choosing the
right data structure can significantly improve the performance and readability of
software systems.
Programs constantly process large amounts of data. Without proper structure,
managing this data would be extremely difficult. Data structures help
programmers store information in ways that make operations such as searching,
inserting, deleting, and updating data efficient.
This guide introduces some of the most important data structures used in
programming:
• Stack
• Queue
• Linked List
• Trees
Each structure is explained with diagrams and Python examples.
Basics of Data Structures
A data structure is a method of organizing and storing data so that it can be
accessed and modified efficiently.
Data structures can be broadly classified into two categories:
1. Linear Data Structures
In linear structures, elements are arranged sequentially.
Examples include:
, • Arrays
• Stacks
• Queues
• Linked Lists
2. Non-Linear Data Structures
In non-linear structures, elements are arranged hierarchically.
Examples include:
• Trees
• Graphs
Understanding these structures helps programmers design efficient algorithms
and solve complex computational problems.
Stack
What is a Stack?
A stack is a linear data structure that follows the LIFO principle (Last In,
First Out).
This means the last element added to the stack is the first one removed.
Example in real life:
A stack of plates in a cafeteria. The last plate placed on the stack is the first one
removed.
Stack Operations
A stack mainly supports two operations:
• Push – adds an element to the stack
• Pop – removes the top element from the stack
Other common operations:
