DATA STRUCTURES
Exam Power Notes • Quick Revision Guide
Description: Concise exam-focused notes covering arrays, linked lists, stacks, queues,
trees, graphs, searching, sorting, complexity, Q&A and MCQs.
Keywords: Data Structures, DSA Notes, Data Structures Exam, Arrays, Linked Lists,
Stack, Queue, Trees, Graphs, Searching, Sorting, Big O, Algorithms, Exam Preparation
1. What is a Data Structure?
A data structure is a way of organizing and storing data so operations such as
access, insertion, deletion and searching can be performed efficiently.
2. Arrays
An array stores elements in an ordered collection and commonly provides direct
access using an index. Operation costs depend on the type and position of the operation.
3. Linked Lists
A linked list consists of nodes. Each node stores data and a reference/link.
Common forms include singly linked lists and doubly linked lists.
4. Stack
A stack follows LIFO (Last In, First Out). Main operations: push, pop and peek/top.
Uses include function calls, undo operations, expression evaluation and backtracking.
5. Queue
A queue follows FIFO (First In, First Out). Main operations: enqueue and dequeue.
Uses include scheduling, buffering and breadth-first search.
6. Trees
A tree is a hierarchical data structure. A binary tree has at most two children
per node. A Binary Search Tree maintains an ordering useful for searching.
Exam Power Notes • Quick Revision Guide
Description: Concise exam-focused notes covering arrays, linked lists, stacks, queues,
trees, graphs, searching, sorting, complexity, Q&A and MCQs.
Keywords: Data Structures, DSA Notes, Data Structures Exam, Arrays, Linked Lists,
Stack, Queue, Trees, Graphs, Searching, Sorting, Big O, Algorithms, Exam Preparation
1. What is a Data Structure?
A data structure is a way of organizing and storing data so operations such as
access, insertion, deletion and searching can be performed efficiently.
2. Arrays
An array stores elements in an ordered collection and commonly provides direct
access using an index. Operation costs depend on the type and position of the operation.
3. Linked Lists
A linked list consists of nodes. Each node stores data and a reference/link.
Common forms include singly linked lists and doubly linked lists.
4. Stack
A stack follows LIFO (Last In, First Out). Main operations: push, pop and peek/top.
Uses include function calls, undo operations, expression evaluation and backtracking.
5. Queue
A queue follows FIFO (First In, First Out). Main operations: enqueue and dequeue.
Uses include scheduling, buffering and breadth-first search.
6. Trees
A tree is a hierarchical data structure. A binary tree has at most two children
per node. A Binary Search Tree maintains an ordering useful for searching.
