Learn DSA from scratch

Pick the language you want to use, learn only the language basics DSA needs, then follow a real topic order with runnable examples and practice links.

Step 1: pick a language

Python

Python suits learners who want concise DSA code and a gentle path from idea to implementation.

Learn DSA in Python

Java

Java suits learners who want explicit types, a broad collections library and code close to what production services use.

Learn DSA in Java

C++

C++ suits learners who want direct control over containers, references and performance, especially for competitive programming.

Learn DSA in C++

JavaScript

JavaScript suits learners who already build for the web and want to practise DSA without switching languages.

Learn DSA in JavaScript

The same tools in each language

Structure	Python	Java	C++	JavaScript
Dynamic array	list	ArrayList	vector	Array
String building	list + str.join	StringBuilder	string / ostringstream	Array + join
Hash map	dict	HashMap	unordered_map	Map
Hash set	set	HashSet	unordered_set	Set
Stack	list	ArrayDeque	stack	Array
Queue	collections.deque	ArrayDeque	queue	Array + head index
Deque	collections.deque	ArrayDeque	deque	Array
Priority queue	heapq	PriorityQueue	priority_queue	None built in
Ordered map	No built-in ordered map	TreeMap	map	None built in
Sorting	list.sort / sorted	Arrays.sort / List.sort	sort / stable_sort	Array.sort

Step 2: What to know before starting DSA

These 11 concepts are the language foundation behind the topic path. Open any language page to see real code for each one.

Step 3: the topic order

The same SDE roadmap order appears on every language page.

Arrays Strings Linked List Binary Trees BST Graph Dynamic Programming Stack Queue Binary Search Backtracking Heap Two Pointers Sliding Window Recursion Math Bit Manipulation Trie Intervals Matrix Sorting Greedy

Step 4: practise and revise

Today All problems Compiler Patterns

Questions, answered

Which language should I learn DSA in?

Choose a language you can read and write comfortably. Python is concise, JavaScript is practical for web developers, Java gives explicit types and collections, and C++ gives direct control with a large STL. The algorithm matters more than the label.

Do I need to know a language before DSA?

Yes. Learn the language basics used in this page first: values and control flow, functions, collections, copying, simple classes or structs, sorting and input. Then start DSA while continuing to practise the language.

How long before I start DSA?

Start once you can write small programs with loops, functions, arrays or lists, maps and sets. You do not need to finish every language feature before learning your first search, sort or linked list.

Can I switch languages later?

Yes. Keep the same topic order and reimplement a few solved problems in the new language. Compare collection operations and numeric behavior instead of memorising a new roadmap.