AVL Tree Practice Tool

A terminal-based interactive learning tool to practice AVL tree insertions, deletions, and rotations. This CLI (Command Line Interface) allows you to explore self-balancing binary search trees with visual feedback and two learning modes: automatic and practice.

Features

• 📈 AVL Tree Visualization: Displays the tree in a clear grid layout with connectors.
• 🤖 Automatic Mode: Automatically balances the tree after insertions/deletions.
• 🧠 Practice Mode: Learn AVL balancing by manually applying the correct rotations.
• 📚 Step-by-Step Guidance: See every rotation explained and shown.
• ⚡ Multiple Commands: Chain multiple commands in a single line (e.g., a 10 a 20 a 30).
• 🔄 Tree Traversals: View preorder, inorder, and postorder traversals.
• 🎨 Color-Coded Display:
  • bright_green for recently added nodes
  • red for unbalanced nodes

Installation

pipx install avltreecli

Make sure you have Python 3.13 installed.

Usage

avltreecli

Commands

Multiple Commands

You can chain multiple commands in a single line for faster operations:

# Add multiple nodes at once
> a 10 a 20 a 30 a 40 a 50

# Mix operations
> a 15 a 25 d 20 a 35

# Quick tree building
> a 50 a 30 a 70 a 20 a 40 a 60 a 80

Configuration

You can change runtime settings with:

config <setting> <value>

Available settings:

Modes

• 🟢 Automatic Mode (default):
  The AVL tree balances itself automatically after every operation. Rotate commands are disabled.

• 🟡 Practice Mode:
  Balance the tree manually with guided hints and validation. Only correct rotations are allowed.

Example Session

# Basic operations
> a 30
Added 30 to the tree

> a 20
Added 20 to the tree

> a 10
Tree is unbalanced! Node 30 has balance factor 2
Step 1: Balancing node 30 (balance: 2)
→ Performing right rotation on node 30
Tree is now balanced!

# Multiple commands in one line
> a 40 a 50 a 60
Added 40 to the tree
Added 50 to the tree
Tree is unbalanced! Node 40 has balance factor -2
Step 1: Balancing node 40 (balance: -2)
→ Performing left rotation on node 40
Added 60 to the tree

# View tree structure
> tree
+---+---+---+---+---+---+---+
|   |   |   | 30|   |   |   |
+---+---+---+---+---+---+---+
|   | 20| < | ╩ | > | 50|   |
+---+---+---+---+---+---+---+
| 10|   |   |   | 40| ╩ | 60|
+---+---+---+---+---+---+---+

# Check traversals
> inorder
Inorder traversal: 10 -> 20 -> 30 -> 40 -> 50 -> 60

Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

License

This project is licensed under the MIT License.