Data Structures & Algorithms (DSA)

Curated solutions to LeetCode problems, algorithm design patterns, and computer science lab assignments.

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📊 Daily LeetCode & Problem Solving Tracker

#	Problem	Topic	Difficulty	Solution	Time	Space	Date Added
0001	Two Sum	Arrays & Hashing	Easy	Python	$O(n)$	$O(n)$	2026-09-08
0217	Contains Duplicate	Arrays & Hashing	Easy	Python	$O(n)$	$O(n)$	2026-09-09
0242	Valid Anagram	Arrays & Hashing	Easy	Python	$O(n)$	$O(1)$	2026-09-10
0049	Group Anagrams	Arrays & Hashing	Medium	Python	$O(N \cdot K)$	$O(N \cdot K)$	2026-09-11
0347	Top K Frequent Elements	Arrays & Hashing	Medium	Python	$O(n)$	$O(n)$	2026-09-12
0238	Product of Array Except Self	Arrays & Hashing	Medium	Python	$O(n)$	$O(1)$	2026-09-12
0036	Valid Sudoku	Arrays & Hashing	Medium	Python	$O(1)$	$O(1)$	2026-09-13
0128	Longest Consecutive Sequence	Arrays & Hashing	Medium	Python	$O(n)$	$O(n)$	2026-09-13

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📚 Lab Assignments

• Lab 1 — Library Borrowing Frequency & Counter Analytics
• Lab 2 — Array Operations & Search Procedures
• Lab 3 — Stack Implementation & Expression Evaluation
• Lab 4 — Queue Architectures & Buffer Management
• Lab 5 — Linked List Manipulation & Traversal
• Lab 6 — Binary Search Trees (BST) & In-order Walk
• Lab 8 — Graph Representation & Traversal (BFS/DFS)

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🛠️ How to Run Tests

Run individual problem solutions directly with Python:

python leetcode/0001_two_sum.py

Or execute all tests using pytest:

pytest leetcode/