Encounter with Algos Complexity analysis Array and linked list Stack and queue Hash table Tree Heap Graph Searching Sorting Divide and conquer Backtracking Dynamic programming Greedy

Data structures and algorithms crash course with animated illustrations and off-the-shelf code

Dive in
GitHub

500 animated illustrations, 14 programming languages, and 3000 community Q&As to help you dive into data structures and algorithms.

Paperbook
Web
PDF

### Endorsements

“An easy-to-understand book on data structures and algorithms, which guides readers to learn by minds-on and hands-on. Strongly recommended for algorithm beginners!”

—— Junhui Deng, Professor, Department of computer science and technology, Tsinghua University

“If I had 'Hello Algo' when I was learning data structures and algorithms, it would have been 10 times easier!”

—— Mu Li, Senior principal scientist, Amazon

### Animated illustrations

It’s crafted for a smooth learning experience.

"A picture is worth a thousand words."

### Off-the-shelf code

One click to run code in multiple languages.

"Talk is cheap. Show me the code."

### Learning together

Don’t hesitate to ask or share your thoughts.

"Learning by teaching."

### Author

Yudong Jin（@krahets）

### Code reviewers

coderonion
Zig, Rust
curtishd
Kotlin
Gonglja
C, C++
gvenusleo
Dart
hpstory
C#
justin-tse
JS, TS
khoaxuantu
Ruby
krahets
Python, Java
night-cruise
Rust
nuomi1
Swift
Reanon
Go, C
rongyi
Rust

### English version reviewers

yuelinxin
K3v123
QiLOL
Phoenix0415
SamJin98
yanedie
RafaelCaso
pengchzn
thomasq0
magentaqin

### Contributors

This book has been refined by the efforts of over 200 contributors. We sincerely thank them for their invaluable time and contributions!