💻 DSA Learning Roadmap 2026

If you're starting Data Structures & Algorithms from scratch, follow this order and practice each topic before moving ahead.

🟢 Part 1 — Programming Fundamentals

• Variables and data types, Operators, Conditions, Loops, Functions

• Recursion basics, Arrays and strings, Input/output, Basic problem solving

🎯 Goal: Become comfortable writing code before starting DSA.

🟢 Part 2 — Complexity Analysis

• Time complexity, Space complexity, Big O notation, Big Ω, Big Θ

• Best, average and worst case, Comparing algorithms, Complexity of common operations

🎯 Goal: Learn to judge whether a solution is efficient.

🟡 Part 3 — Arrays

• Traversal, Searching, Insertion and deletion, Prefix sums

• Two pointers, Sliding window, Kadane's algorithm, Sorting-based problems, Subarrays

🎯 Goal: Solve common array problems efficiently.

🟡 Part 4 — Strings

• String manipulation, Character frequency, Palindromes, Anagrams, Substrings

• Two pointers, Sliding window, String hashing basics

🟡 Part 5 — Searching & Sorting

Learn:

• Searching: Linear search, Binary search, Binary search on answer

• Sorting: Bubble sort, Selection sort, Insertion sort, Merge sort, Quick sort, Counting sort, Heap sort

🎯 Goal: Understand both the algorithms and when to use them.

🔵 Part 6 — Linked Lists

• Singly linked list, Doubly linked list, Circular linked list

• Insert/delete, Reverse a linked list, Fast & slow pointers, Cycle detection, Merge linked lists, Find middle node

🔵 Part 7 — Stack & Queue

• Stack: Push/pop, Applications, Balanced parentheses, Monotonic stack, Next greater element

• Queue: Enqueue/dequeue, Circular queue, Deque, Priority queue

🟣 Part 8 — Hashing

• Hash tables, Hash maps, Hash sets, Frequency counting

• Duplicate detection, Two-sum pattern, Prefix-sum + hashing, Collision concepts

🎯 Goal: Learn how hashing can reduce many problems from O(n²) to O(n).

🟣 Part 9 — Recursion & Backtracking

• Recursion fundamentals, Base cases, Recursive trees

• Subsets, Subsequences, Permutations, Combination problems, N-Queens, Sudoku, Maze problems

🟠 Part 10 — Trees

• Binary trees, Tree terminology, DFS, BFS, Preorder, Inorder, Postorder, Level-order traversal

• Height/depth, Diameter, Balanced trees, Lowest Common Ancestor

🟠 Part 11 — Binary Search Trees

• BST properties, Search, Insert, Delete, Minimum/maximum, Successor/predecessor, Validate BST, LCA in BST

🔴 Part 12 — Heap & Priority Queue

• Min heap, Max heap, Heapify, Insert/delete, Priority queue

• Top K problems, Kth largest/smallest, Heap sort, Merge K sorted lists

🔴 Part 13 — Graphs

• Graph representation, Adjacency matrix, Adjacency list, BFS, DFS

• Connected components, Cycle detection, Bipartite graphs, Topological sorting

🔴 Part 14 — Advanced Graph Algorithms

• Dijkstra, Bellman-Ford, Floyd-Warshall, Minimum Spanning Tree

• Prim's algorithm, Kruskal's algorithm, Disjoint Set Union, Strongly connected components, Shortest paths

🟤 Part 15 — Greedy Algorithms

• Greedy strategy, Activity selection, Fractional knapsack, Job scheduling, Interval problems, Minimum platforms, Huffman coding

🎯 Goal: Learn when making the locally optimal choice leads to a global solution.