Collatz Conjecture in C
Calculate the number of steps to reach 1 using the Collatz conjecture
exercism fetch c 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.
Starting with n = 12, the steps would be as follows:
Resulting in 9 steps. So for input n = 12, the return value would be 9.
Make sure you have read the C page on the Exercism site. This covers the basic information on setting up the development environment expected by the exercises.
Passing the Tests
Get the first test compiling, linking and passing by following the three rules of test-driven development.
The included makefile can be used to create and run the tests using the
Create just the functions you need to satisfy any compiler errors and get the test to fail. Then write just enough code to get the test to pass. Once you've done that, move onto the next test.
As you progress through the tests, take the time to refactor your implementation for readability and expressiveness and then go on to the next test.
Try to use standard C99 facilities in preference to writing your own low-level algorithms or facilities by hand.
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.