ryanmarcus/reverse_collatz

A Rust program with various methods for calcuating members of A033491, that is, the smallest integer with a given Collatz length

Reverse Collatz Calculator

Built with this Rust:

rustc 1.0.0-nightly (522d09dfe 2015-02-19) (built 2015-02-20)

And this cargo:

cargo 0.0.1-pre-nightly (3f74d7e 2015-02-14) (built 2015-02-14)

To compile an executable, do:

cargo build --release

To just run it, do:

cargo run 6 # where 6 is the sequence length

To run the tests, do:

cargo test

The default method used is a simple iterative search that starts at 1. Inclded methods that are (and tested):

• A simple iterative search that starts at 1 (default)
• A recursive backtracking algorithm that searches the Collatz tree (recursive.rs)
• An iterative triangular expansion method that searches the Collatz tree (triangular_expansion.rs)

Copyright 2015 Ryan Marcus

This file is part of reverse_collatz.

reverse_collatz is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

reverse_collatz is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with reverse_collatz. If not, see http://www.gnu.org/licenses/.