LeetCodePatterns

Master the essential patterns tested by FAANG, trading firms, and top tech companies. Focus your preparation on what actually gets asked in interviews.

Essential Patterns

80%

Interview Coverage

200

Practice Problems

🎯 Essential Patterns

👆

Two Pointers

Use two pointers to traverse arrays or strings efficiently

Two Sum II, 3Sum, Container With Most Water

Companies: Google, Meta, Apple

🪟

Sliding Window

Maintain a window of elements for subarray problems

Longest Substring, Min Window Substring

Companies: Amazon, Microsoft, Uber

🔍

Binary Search

Efficiently search sorted arrays or search spaces

Search in Rotated Array, Find Peak Element

Companies: Google, Bloomberg, Jane Street

🌳

DFS/BFS

Tree and graph traversal algorithms

Binary Tree Paths, Number of Islands

Companies: Meta, LinkedIn, Airbnb

🧩

Dynamic Programming

Break problems into overlapping subproblems

Climbing Stairs, Coin Change, LIS

Companies: Google, Citadel, Two Sigma

↩️

Backtracking

Explore all possibilities with constraint satisfaction

Permutations, Subsets, N-Queens

Companies: Apple, Netflix, Palantir

🏢 Company Focus Areas

🚀 FAANG Companies

Top Patterns

• Array/String manipulation (Two Pointers, Sliding Window)
• Tree traversal (DFS/BFS, Binary Tree problems)
• Dynamic Programming (1D/2D DP, memoization)
• Graph algorithms (BFS for shortest path)

Interview Style: Focus on clean code, edge cases, and optimization discussions

💹 Trading Firms

Key Patterns

• Binary Search (price optimization, search problems)
• Greedy algorithms (scheduling, interval problems)
• Math/Statistics (probability, combinatorics)
• Data structures (heaps, stacks, queues)

Interview Style: Emphasis on mathematical thinking and optimal time/space complexity

📚 Preparation Strategy

📅 8-Week Study Plan

Weeks 1-2: Arrays & Strings

Two Pointers, Sliding Window (30 problems)

Weeks 3-4: Trees & Graphs

DFS/BFS, Binary Trees (25 problems)

Weeks 5-6: Dynamic Programming

1D/2D DP, memoization (20 problems)

Weeks 7-8: Mock Interviews

Mixed problems, time pressure (15 problems/week)

💻 Online Assessment Tips

Before the Test

• Test your environment (camera, mic, internet)
• Practice on the actual platform (HackerRank, Codility)
• Review common patterns in your target language

During the Test

• Read ALL problems first, start with easiest
• Write clean, well-commented code
• Test with edge cases before submitting
• Manage time: don't get stuck on one problem

🛠️ Essential Resources

Practice Platforms

• LeetCode: Pattern-based practice
• NeetCode: Curated problem lists
• AlgoExpert: Video explanations
• Pramp: Mock interviews

Study Materials

• Grokking Coding Patterns: Pattern mastery
• CTCI: Interview fundamentals
• Blind 75: Essential problems
• Company tagged problems: Target practice

Time Management

• Easy problems: 10-15 minutes
• Medium problems: 20-30 minutes
• Hard problems: 35-45 minutes
• Mock interviews: 2-3 per week