Dictionary Definition: Quantities, characters, or symbols on which operations are performed by a computer, stored and transmitted in the form of electrical signals.
Example: Performing operations on data implies they can be stored and transmitted.
Data vs. Information
Data: Collection of characters or symbols without inherent meaning.
Information: Processed data that has meaning (e.g., reversing a string to make it readable).
Key Insight: Data needs to be managed systematically to produce meaningful information.
Importance of Data Structures
Purpose: A systematic way to organize data for efficient usage (both in terms of time and space).
Example: Arrays as a classical data structure to store sequences of elements (e.g., integers, characters).
Example of Array
Instead of multiple variables for similar data, use arrays.
Example: Storing 100 integers in a single array vs. 100 variables.
Strings as sequences of characters can also be stored in arrays.
Real-Life Examples of Data Structures
1. Stack Data Structure
Use Case: Implementing redo and undo features.
Application: Google Docs, PowerPoint, Microsoft Word.
Mechanism:
Undo: Pops top element from the undo stack, places in redo stack.
Redo: Pops top element from redo stack, places back in undo stack.
2. Bitmap Images
Data Structure Used: Array
Mechanism:
Bitmap images are stored as tiny dots called pixels.
Pixels stored in a two-dimensional array to form an image.
Example: A 37x40 2D array to store a Pikachu image.