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CS CoreBeginner

Data Structures & Algorithms

From absolute zero to advanced — no CS degree needed. Every concept explained in plain English with C code.

DSA cheat sheet and project ideas →

Self-paced March 2026
🎓Complete freshers — zero knowledge required
🔄Non-IT background switching to tech
💼Anyone preparing for coding interviews
📱Students who want real understanding, not just code
20
Lessons
92+
Topics covered
29h
Total content
C
Language used
100%
Free forever
💡 Note
Why do we use C? — C forces you to understand what is actually happening in memory. No garbage collector, no shortcuts. When you learn DSA in C, you truly understand how data is stored and manipulated. Every other language becomes easier after this. You do not need to know C before starting — we teach you exactly what you need, when you need it.
🎯 Pro Tip
Prerequisites: None. Absolutely zero. If you can use a computer and type, you can start the first lesson right now. No math degree, no prior coding, no CS background required.
// Curriculum

20 Lessons. Zero to Advanced.

Go in order. Each lesson builds on the last. Do not skip — every concept is introduced exactly when you need it, not before.

LESSON 1✓ LIVE

Before We Write Code

What DSA actually is, why every tech company tests it, how your computer stores data, and writing your very first C program.

What is DSA & why it mattersHow computers thinkWhy C for DSAYour first C program
45 min
read time
Start →
LESSON 2✓ LIVE

Complexity — The Scoreboard for Code

Learn to measure how fast and how memory-hungry any piece of code is. This is what separates good code from great code.

Time ComplexitySpace ComplexityBig O NotationBest / Worst / Average CaseAnalyzing any code
60 min
read time
Start →
LESSON 3✓ LIVE

Arrays

The foundation of every data structure. Boxes lined up in memory — simple to understand, used everywhere.

What is an ArrayInsert & DeleteTraversal2D ArraysCommon problems
90 min
read time
Start →
LESSON 4✓ LIVE

Strings

Text is just an array of characters. Learn how computers store and manipulate words, sentences, and names.

Strings in CReverse & PalindromeAnagram checkPattern matching basics
60 min
read time
Start →
LESSON 5✓ LIVE

Pointers

The concept that confuses 90% of beginners — explained so clearly you'll wonder why everyone makes it complicated.

Memory addressesWhat is a pointer& and * operatorsPointers + arraysCommon mistakes
75 min
read time
Start →
LESSON 6✓ LIVE

Linked Lists

A chain of nodes where each one points to the next. More flexible than arrays — and a favourite in interviews.

Singly Linked ListDoubly Linked ListCircular Linked ListReverse a listDetect a loop
90 min
read time
Start →
LESSON 7✓ LIVE

Stacks

Last In, First Out. Like a stack of plates — you always pick from the top. Powers undo/redo and function calls.

Stack using arrayStack using linked listBalanced parenthesesFunction call stack
60 min
read time
Start →
LESSON 8✓ LIVE

Queues

First In, First Out. Like a ticket counter line. Powers everything from CPU scheduling to WhatsApp message delivery.

Queue using arrayCircular QueueDequePriority QueueReal-world uses
60 min
read time
Start →
LESSON 9✓ LIVE

Recursion

A function that calls itself. The concept that breaks most beginners — we'll make it click with the clearest explanation ever written.

Base case vs recursive caseTracing call stacksFactorial & FibonacciTower of Hanoi
90 min
read time
Start →
LESSON 10✓ LIVE

Sorting Algorithms

Six ways to arrange data in order — from the simplest to the fastest. Every algorithm explained with step-by-step visuals.

Bubble, Selection, InsertionMerge SortQuick SortCounting SortBig O comparison
120 min
read time
Start →
LESSON 11✓ LIVE

Searching Algorithms

Linear search checks every item. Binary search cuts the problem in half each time. Learn when and why to use each.

Linear SearchBinary SearchIterative vs RecursiveBinary Search variations
45 min
read time
Start →
LESSON 12✓ LIVE

Trees

Hierarchical data — like a company org chart. The most important non-linear structure you'll ever learn.

Tree terminologyBinary Tree in CInorder / Preorder / PostorderLevel Order traversal
90 min
read time
Start →
LESSON 13✓ LIVE

Binary Search Tree

A tree with a rule: left is smaller, right is bigger. Enables search, insert, and delete in O(log n).

BST propertyInsert & SearchDelete (3 cases)Balanced vs Unbalanced
75 min
read time
Start →
LESSON 14✓ LIVE

Heaps

A tree where the parent is always larger (or smaller) than its children. Powers priority queues and heap sort.

Min Heap vs Max HeapHeap as arrayInsert & DeleteHeap Sort
75 min
read time
Start →
LESSON 15✓ LIVE

Hashing

Look up anything in O(1) time. Hash tables are behind almost every fast system you've used — search, login, caching.

Hash functionsCollisionsChainingOpen AddressingBuild one in C
75 min
read time
Start →
LESSON 16✓ LIVE

Graphs

Nodes connected by edges. Maps, social networks, flight routes — almost every real-world relationship is a graph.

Graph typesAdjacency list/matrixBFS & DFSDijkstra'sTopological Sort
120 min
read time
Start →
LESSON 17✓ LIVE

Dynamic Programming

Remember answers you've already computed. DP turns exponential problems into polynomial ones — the hardest concept, explained from scratch.

MemoizationTabulationKnapsackLCSCoin ChangeEdit Distance
150 min
read time
Start →
LESSON 18✓ LIVE

Greedy Algorithms

Always pick the best option right now. Sometimes that's enough — and it's much faster than trying everything.

Activity SelectionFractional KnapsackHuffman CodingGreedy vs DP
75 min
read time
Start →
LESSON 19✓ LIVE

Backtracking

Try a path. Hit a dead end. Go back. Try another. Backtracking is how computers solve puzzles — N-Queens, Sudoku, mazes.

N-QueensRat in a MazeSudoku SolverSubset Sum
90 min
read time
Start →
LESSON 20✓ LIVE

Advanced Topics

Segment Trees, Tries, DSU, Sliding Window, Two Pointers, Bit Manipulation — the techniques that separate good engineers from great ones.

Segment TreeTrieUnion-FindSliding WindowTwo PointersBit Manipulation
180 min
read time
Start →
// Ready to start?

All 20 lessons are live.

Start with lesson 1 and go in order. Your progress saves in this browser, so you can come back and pick up where you left off.

What to learn next
Introduction to DSA
DSA · 10 min
Time & Space Complexity
DSA · 12 min
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