LeetCode Patterns
The repeating algorithmic patterns that cover 80% of technical coding interview problems.
Definition
Rather than memorizing thousands of individual problems, LeetCode patterns are a set of ~14 core algorithmic templates — such as Two Pointers, Sliding Window, BFS/DFS, and Dynamic Programming — that can solve the vast majority of coding interview questions when applied correctly. LeetCode hosts over 3,000 problems as of 2025, but research by NeetCode and other prep educators shows that ~150 curated problems across 14 patterns cover the vast majority of what top companies test.
Why It Matters in Interviews
Top companies like Google, Meta, and Amazon use coding interviews to evaluate problem-solving ability and pattern recognition. According to a widely cited Tech Interview Handbook analysis (Grind 75), candidates who practice a curated, pattern-focused set solve problems 3–5x faster in real interviews than those approaching each problem as unique. At Meta, engineers report that nearly all coding questions map to a small number of recognizable patterns.
How to Use It
Study each pattern in isolation until you can code the template from memory. Then practice identifying which pattern applies to a new problem before writing any code. The key skill is pattern recognition, not memorization.
Quick Tips
- The 6 highest-yield patterns: Two Pointers, Sliding Window, Tree BFS/DFS, Dynamic Programming, Binary Search, and Graph traversal.
- Time yourself. Companies care about efficiency — practice solving Easy problems in <10 min, Medium in <20 min.
- After solving any problem, look up 3 alternative solutions. Understanding trade-offs is what separates Good from Great.
- Practice explaining your approach out loud — silent coding is a red flag in real interviews.
FAQ
How many LeetCode problems should I solve before an interview?
Quality over quantity. 100 deeply understood problems with pattern mastery beats 500 memorized solutions. Focus on 50–75 problems per pattern category you plan to cover.