Kaprekar's Constant Explorer

A Python script that explores the fascinating mathematical phenomenon of Kaprekar's constant (6174) using the rich library for beautiful console output.

What is Kaprekar's Constant?

Kaprekar's constant is 6174, discovered by Indian mathematician D. R. Kaprekar. The process works as follows:

1. Take any 4-digit number where all digits are different
2. Arrange the digits in descending order (A)
3. Arrange the digits in ascending order (B)
4. Calculate A - B
5. Repeat the process with the result
6. Eventually, you will reach 6174, and it will stay at 6174

Features

• ✅ Input validation for 4-digit numbers with unique digits
• ✅ Beautiful console output using the rich library
• ✅ Step-by-step visualization of the process
• ✅ Configurable step limit (default: 50)
• ✅ Interactive mode with multiple number testing
• ✅ Progress indicators and colored output

Installation

1. Install the required dependency:

pip install -r requirements.txt

Usage

Run the script:

python3 kaprekar_explorer.py

The script will prompt you to enter a 4-digit number with all different digits. It will then show you the step-by-step process until it reaches 6174 or hits the step limit.

Example

Enter a 4-digit number: 1234

Step-by-Step Sequence:
┌──────┬────────┬────────────────────────────┐
│ Step │ Number │ Process                    │
├──────┼────────┼────────────────────────────┤
│ Start│ 1234   │ Initial number             │
│ 1    │ 3087   │ 4321 - 1234 = 3087         │
│ 2    │ 8352   │ 8730 - 0378 = 8352         │
│ 3    │ 6174   │ 8532 - 2358 = 6174         │
└──────┴────────┴────────────────────────────┘

Requirements

• Python 3.6+
• rich library (>=13.0.0)

Notes

• The script validates that all 4 digits are different
• There's a default limit of 50 steps to prevent infinite loops
• The process always converges to 6174 for valid inputs