# Collatz Conjecture in Elixir

#### Calculate the number of steps to reach 1 using the Collatz conjecture

1 | ```
exercism fetch elixir collatz-conjecture
``` |

# 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:

- 12
- 6
- 3
- 10
- 5
- 16
- 8
- 4
- 2
- 1

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

## Running tests

Execute the tests with:

1 |
```
$ elixir bob_test.exs
``` |

(Replace `bob_test.exs`

with the name of the test file.)

### Pending tests

In the test suites, all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by
commenting out the relevant `@tag :pending`

with a `#`

symbol.

For example:

Or, you can enable all the tests by commenting out the
`ExUnit.configure`

line in the test suite.

1 |
```
# ExUnit.configure exclude: :pending, trace: true
``` |

For more detailed information about the Elixir track, please see the help page.

## Source

An unsolved problem in mathematics named after mathematician Lothar Collatz 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.