Sha256: 75150c621bbfac14bdf9018e212b0d3ca8475826a67ed38207a94750ba661eef

Contents?: true

Size: 1.55 KB

Versions: 79

Compression:

Stored size: 1.55 KB

Contents

# Collatz Conjecture

The Collatz Conjecture or 3x+1 problem can be summarized as follows:

Take any positive integer n. If n is even, divide n by 2 to get n / 2. If n is
odd, multiply n by 3 and add 1 to get 3n + 1. Repeat the process indefinitely.
The conjecture states that no matter which number you start with, you will
always reach 1 eventually.

Given a number n, return the number of steps required to reach 1.

## Examples

Starting with n = 12, the steps would be as follows:

0. 12
1. 6
2. 3
3. 10
4. 5
5. 16
6. 8
7. 4
8. 2
9. 1

Resulting in 9 steps. So for input n = 12, the return value would be 9.

* * * *

For installation and learning resources, refer to the
[exercism help page](http://exercism.io/languages/ruby).

For running the tests provided, you will need the Minitest gem. Open a
terminal window and run the following command to install minitest:

    gem install minitest

If you would like color output, you can `require 'minitest/pride'` in
the test file, or note the alternative instruction, below, for running
the test file.

Run the tests from the exercise directory using the following command:

    ruby collatz_conjecture_test.rb

To include color from the command line:

    ruby -r minitest/pride collatz_conjecture_test.rb


## Source

An unsolved problem in mathematics named after mathematician Lothar Collatz [https://en.wikipedia.org/wiki/3x_%2B_1_problem](https://en.wikipedia.org/wiki/3x_%2B_1_problem)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.

Version data entries

79 entries across 79 versions & 1 rubygems

Version Path
trackler-2.2.1.159 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.158 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.157 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.156 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.155 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.154 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.153 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.152 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.151 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.150 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.149 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.148 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.147 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.146 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.145 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.144 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.143 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.142 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.141 tracks/ruby/exercises/collatz-conjecture/README.md
trackler-2.2.1.140 tracks/ruby/exercises/collatz-conjecture/README.md