How to calculate Fibonacci numbers using Divide and Conquer?

Question

C++ / C#

It is necessary to somehow write a program for calculating the Black Sea Fleet using divide and conquer, but how to do this is not very clear, there is almost no information on the Internet, these formulas do not lead me to anything.
The task itself:

Answer 1

The calculation of the Fibonacci number is not necessarily implemented through recursion! If the author has fallen in love with all the exercises on the tower, then it is inappropriate to do a "lab" for him. Rules like it is forbidden to request rhenium mathematical problems.
https://habr.com/en/post/261159/