Handwritten notes · Part 11
DSA Handwritten Notes for Placements (Free PDF)
By Gaurav SharmaPublished
26 pages of handwritten-style DSA notes for placements and coding interviews: Big-O, sliding window, two pointers, binary search, linked lists, trees, heaps, graphs, Dijkstra, union-find, greedy and dynamic programming, with clean C++ templates and Hinglish explanations.
- Pages
- 26
- Format
- A4 PDF
- Language
- English + Hinglish
- Price
- Free by email
What's inside
24 topics, one page each
- 01Big-O, complexity classes and reading constraints
- 02Recursion and backtracking
- 03Prefix sums, two pointers and Kadane's algorithm
- 04Sliding window: fixed and variable
- 05Hashing patterns: two sum, subarray sum equals k
- 06Binary search, lower bound and search on the answer
- 07Sorting algorithms and their complexities
- 08Linked list: reverse, middle, Floyd's cycle detection
- 09Stack, queue and the monotonic stack
- 10Trees and the four traversals
- 11Binary search trees: search, insert, validate, LCA
- 12Tree problems: height, diameter, level order
- 13Heaps and top-K problems
- 14Graphs: representation, BFS and DFS
- 15Topological sort and cycle detection
- 16Shortest paths: Dijkstra, Bellman-Ford, Floyd-Warshall
- 17Union-find and minimum spanning trees
- 18Greedy algorithms and when they fail
- 19Dynamic programming: memoization vs tabulation
- 20DP: 0/1 knapsack and longest increasing subsequence
- 21DP: longest common subsequence and coin change
- 22Bit manipulation tricks and tries
- 23Which pattern to use, plus a complexity quiz
- 24Last-minute revision cheat sheet
DSA rounds reward recognising patterns, not memorising thousands of problems. These notes give each important pattern one page: when to use it, a short C++ template you can write from memory, its complexity, and the classic problems it solves.
What makes these DSA notes different?
- Templates, not just theory. Sliding window, binary search on the answer, monotonic stack, BFS, Dijkstra, Kahn's topological sort, union-find and DP, each in a few clean lines of C++.
- "Which pattern?" table. A one-page map from what the problem says to what to try first.
- The traps that cause wrong answers. Mid-point overflow, validating a BST the wrong way, greedy failing on coin change, and the knapsack loop direction.
- Hinglish where it helps. Recursion, sliding window, heaps and DP each get a short Hinglish explanation.
How should you use these DSA notes?
Write each template once from memory, then solve three to five problems of that pattern. Use the complexity table to check your approach against the constraints before you code, and the last page as a revision sheet before the interview.
This is Part 11 of the series. For the C++ STL used in the code, see the C++ handwritten notes.
FAQ
Questions about these notes
Are these DSA notes really free?
Yes. The full 26-page PDF is free; email me to request the complete PDF. Share it with friends preparing for placements.
Which language is the code in?
C++, the most common choice for DSA rounds. The templates are short and use the STL; the C++ handwritten notes (Part 2) cover the STL itself. The logic carries over directly to Java or Python.
Do the notes teach how to recognise which pattern to use?
Yes. One page maps problem signals to patterns, for example 'longest substring with a rule' to sliding window or 'minimum value that works' to binary search on the answer, and every pattern page lists the classic problems it solves.
Is dynamic programming explained for beginners?
Yes. A 4-step recipe (state, transition, base cases, order), memoization vs tabulation, then worked 0/1 knapsack, LIS, LCS and coin change with the common loop-order traps.
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