Sturmian word

From Rosetta Code
Revision as of 22:47, 31 January 2024 by imported>CosmiaNebula
Task
Sturmian word
You are encouraged to solve this task according to the task description, using any language you may know.

A Sturmian word is a binary sequence, finite or infinite, that makes up the cutting sequence for a positive real number x, as shown in the picture.

Example Sturmian word when x = 0.618..., the golden ratio.

The Sturmian word can be computed thus as an algorithm:

  • If , then it is the inverse of the Sturmian word for . So we have reduced to the case of .
  • Iterate over
  • If is an integer, then the program terminates. Else, if , then the program outputs 0, else, it outputs 10.

The problem:

  • Given a positive rational number , specified by two positive integers , output its entire Sturmian word.
  • Given a quadratic real number , specified by three positive integers , where is not a perfect square, output the first letters of its Sturmian word when given a positive number .

(If the programming language can represent infinite data structures, then that works too.)

Stretch goal: calculate the Sturmian word for other kinds of definable real numbers, such as cubic roots.