Introduction to Data Structures & Algorithms
So far in C programming, you have learned how to store data using variables, arrays, structures, and files.
But as programs grow larger, the way data is organized becomes more important than just storing it.
This is where Data Structures and Algorithms (DSA) come in.
What Is a Data Structure?
A data structure is a method of organizing and storing data so that it can be used efficiently.
It is not just about data — it is about how data is arranged in memory.
Examples you already know:
- Arrays
- Structures
- Files
What Is an Algorithm?
An algorithm is a step-by-step procedure used to solve a problem.
It defines:
- How data is processed
- How decisions are made
- How tasks are completed efficiently
Example:
Searching a number in a list is an algorithm.
Why Do We Need DSA?
Imagine a program that works correctly but is very slow.
In real-world applications, speed and efficiency matter.
DSA helps programs:
- Run faster
- Use less memory
- Scale for large data
Real-World Analogy
Think of a library:
- Books arranged randomly → difficult to find
- Books arranged by category and index → easy to find
The arrangement is the data structure.
The search method is the algorithm.
Common Data Structures
- Arrays
- Linked Lists
- Stacks
- Queues
- Trees
- Graphs
Common Algorithms
- Searching algorithms
- Sorting algorithms
- Traversal algorithms
How DSA Is Used in Real Applications
- Databases
- Operating systems
- Web search engines
- Navigation apps
Mini Practice
- Think of how contacts are stored in a phone
- Which data structure would be efficient?
Quick Quiz
Q1. What is a data structure?
Q2. What is an algorithm?
Q3. Why is efficiency important?
Q4. Are arrays a data structure?
Q5. Does DSA matter in real software?