📚 Coding DSA Interview at Big Tech — 14 Core Pattern Chapters

A systematic, pattern-first companion repository inspired by the Big Tech DSA Coding Interview curriculum. Includes all 14 foundational-to-advanced pattern chapters, complete with clean Python 3 solutions, formal Big-O analysis, UMPIRE interview guides, and executable test suites.

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🎯 Frontmatter & Interview Playbooks

• 📖 0.1 Foreword & How to Use This Book — 3 reading paths (Sequential, Pattern-based, Last-minute cramming).
• 🧩 0.2 The UMPIRE Interview Framework — 6-step problem-solving system: Understand ➜ Match ➜ Plan ➜ Implement ➜ Review ➜ Evaluate.
• ⏱️ 0.3 Big-O in 30 Minutes — Asymptotic analysis, amortized complexity, practical constraint bounds.
• 🐍 0.4 Python 3 Cheatsheet for Interviews — Data structures, syntax, heap tricks, and critical pitfalls.
• 🎤 0.5 Whiteboard & CoderPad Presentation Guide — Communication etiquette, thinking out loud, and handling hints.

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🗺️ Curriculum Roadmap & 14 Pattern Chapters

Chapter	Topic & Core Pattern	Difficulty	Key Problems & Solutions	Code & Study Guide
01	Chapter 1 — Array	🟢 Basic	Two Sum, Stock Profit, Product Except Self, Kadane's	Open Chapter 📂
02	Chapter 2 — String	🟢 Basic	Valid Anagram, Palindrome, Longest Substring Window	Open Chapter 📂
03	Chapter 3 — Recursion	🟡 Intermediate	Climbing Stairs Memoization, Subsets (Power Set)	Open Chapter 📂
04	Chapter 4 — Sorting	🟡 Intermediate	Merge Sort, Dutch National Flag (Sort Colors)	Open Chapter 📂
05	Chapter 5 — Binary Search	🟡 Intermediate	Classic Binary Search, Rotated Array Search	Open Chapter 📂
06	Chapter 6 — Hash Table	🟢 Basic	Longest Consecutive Sequence, Subarray Sum Equals K	Open Chapter 📂
07	Chapter 7 — Linked List	🟡 Intermediate	Reverse Linked List, Floyd's Tortoise & Hare Cycle	Open Chapter 📂
08	Chapter 8 — Queue + Stack	🟡 Intermediate	Valid Parentheses, Daily Temperatures Monotonic Stack	Open Chapter 📂
09	Chapter 9 — Graph	🔴 Advanced	Clone Graph, Disjoint Set Union (Union-Find)	Open Chapter 📂
10	Chapter 10 — Breadth-First Search (BFS)	🟡 Intermediate	Tree Level-Order, Shortest Path in Binary Matrix	Open Chapter 📂
11	Chapter 11 — Depth-First Search (DFS)	🟡 Intermediate	Course Schedule 3-State Cycle Detection	Open Chapter 📂
12	Chapter 12 — Island Matrix Traversal	🟡 Intermediate	Number of Islands DFS, Rotting Oranges Multi-Source BFS	Open Chapter 📂
13	Chapter 13 — Topological Sort	🔴 Advanced	Kahn's Indegree Algorithm (Course Schedule II)	Open Chapter 📂
14	Chapter 14 — Interval	🟡 Intermediate	Merge Intervals, Meeting Rooms II Minimum Allocation	Open Chapter 📂

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🌟 Author & Credits

• GitHub: @preyal2
• Repository: preyal2/coding-interview-patterns
• Original Authors & Inspiration: Phạm Ngọc Lâm & Lê Quang Hoà (EngineerPro Coding Book)