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Encounter with Algos Complexity Analysis Array and Linked List Stack and Queue Hashing Tree Heap Graph Searching Sorting Divide and Conquer Backtracking Dynamic Programming Greedy

Data structures and algorithms tutorial with animated illustrations and ready-to-run code

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500 animated illustrations, 14 programming languages, and 3,000 community Q&As to help you get started with data structures and algorithms.

### Endorsements

“An easy-to-understand introduction to data structures and algorithms that encourages readers to engage both mind and hands. Highly recommended for 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."

### One-Click Runnable Code

Run code in multiple languages with one click.

"Talk is cheap. Show me the code."

### Learn Together

Ask questions, discuss ideas, and learn with others.

"Learning by teaching."

### Author

Yudong Jin（@krahets）

### Translators

The English version of this book was reviewed by the following contributors. We thank them for their time and effort.

yuelinxin
K3v123
magentaqin
QiLOL
Phoenix0415
SamJin98
yanedie
RafaelCaso
pengchzn
thomasq0

### Code Reviewers

The multilingual code versions of this book were made possible by the following developers. We appreciate their efforts and contributions!

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

### Contributors

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