Collatz Conjecture Tester

Fast C++ implementation for testing the Collatz conjecture on single numbers or ranges.

The Collatz Conjecture

For any positive integer n, repeatedly apply:

• If n is even: n → n/2
• If n is odd: n → 3n + 1

The conjecture states that this sequence always reaches 1.

Build

# Single-threaded version
g++ -O3 -std=c++11 collatz.cpp -o collatz

# With OpenMP for parallel processing
g++ -O3 -std=c++11 -fopenmp collatz.cpp -o collatz

Usage

# Test single number
./collatz 27

# Test range
./collatz 1 1000000

# Test range with sample sequences
./collatz 1 1000000 --sample

Features

• Efficient caching to avoid recomputation
• OpenMP parallelization for range testing
• Tracks peak values and growth ratios
• Overflow protection for large sequences
• Progress reporting for large ranges

License

MIT License