PAT
Learn to recognise
Pattern Guides
Every coding pattern with the instinct that triggers it, a memory hack, a reusable Java template and the classic problems to practise.
49Patterns
7Families
5Easy
34Medium
10Hard
0%0 / 49
01Arrays & Strings
10
02Linear Structures
6
03Search & Sort
6
04Trees & Heaps
9
05Graphs
6
06Dynamic Programming
10
07Math & Strings
2
No problems match these filters.
How to use this track
Each pattern guide explains one technique: the instinct that tells you to use it, a memory hack, a reusable Java template, common variations and mistakes, and practice problems from easy to hard.
Read a guide, type the template from memory, then solve two or three of its practice problems. Mark the guide as learned only when you can explain when to use the pattern and when not to.
For a quick refresher before an interview, use the one-page DSA cheat sheet, which summarises the 13 core patterns and links back to these guides.