Master LeetCode Patterns

Pattern Recognition Training

LeetCode Patterns: Learn Algorithm Patterns with Interactive Quizzes

Build intuition for solving LeetCode problems with Duolingo-style learning. Progressive difficulty, instant feedback, and gamified progress tracking.

Interactive quizzes
Pattern‑first explanations
Copy‑paste templates

What you'll learn: sliding window, two pointers, binary search (lower/upper bound, search on answer), dynamic programming (1D and 2D grid), graph algorithms (BFS/DFS, Dijkstra), prefix/suffix sums, monotonic stack, trie, and union-find.

Fundamentals

New to these topics? Start with Big‑O, Arrays & Strings, Linked Lists, Stacks/Queues/Heaps, Trees, Graphs, and Dynamic Programming.

Collections

Curated problem sets grouped by pattern. Start with Sliding Window, Two Pointers, and Dynamic Programming.

Filters:

39 patterns found

Featured Categories

A quick start across our most‑used topics

Arrays & Strings

Opposite-ends, partitioning, read/write compaction

Fixed/variable windows, frequency maps, deque patterns

Intermediate10Q

Prefix sums, XOR, difference arrays, rolling prefix

Frequency maps, group-by, first/last index tracking

Intermediate10Q

Sorting + Greedy

Custom comparators, merge intervals, bucket sort

Intermediate18Q

Boundary search, rotated arrays, search on answer

Monotonic Stack

Next greater/smaller, largest rectangle, stock span

Monotonic Deque

Window max/min, shortest subarray, convex hull trick

Interval endpoints, plane sweep, timeline concurrency

Graphs

Intermediate12Q

Components, islands, cycle detection, bipartite

Topological Sort

Kahn's algorithm, DFS-based, detect cycles in DAG

Dijkstra, 0-1 BFS, Bellman-Ford, multi-source

Union-Find (DSU)

Connectivity, Kruskal MST, offline queries

Kruskal's and Prim's algorithms

Kosaraju's and Tarjan's algorithms

Dynamic Programming

Intermediate12Q

Kadane, house robber, stocks, LIS

Intermediate10Q

Unique paths, min cost path, shapes

Edit distance, LCS, palindromic subsequence

Burst balloons, matrix chain, merge stones

Intermediate10Q

0/1, unbounded, bounded, multi-dimensional

TSP, assignment, DP over subsets

Count numbers with properties, tight/loose states

50+

Algorithm Patterns

500+

Practice Questions

10k+

Developers Learning