You will need to optimise your code. For example, what is the big O lookup time for a C# List? Are there faster implementations?

I

Yeah I think you're right actually, that looks better, I shall rework this kata

I struggled with this too. It's extremely unclear in the description how the fitness function works. However using
fitness.call(chromosome.to_i(2)) returns a rational answer when chromosome is a binary string.

This returns true for an invalid sudoku board composed entirely of 5s
validSolution(Array.new(9){Array.new(9){5}}) == true

Thanks for your questions

1. a is meaningless in counting operation.
2. Operations 4+ are tetration, pentation etc however, my solution to the problem couldn't calculate anything larger than n = 3 because it would hit max call stack
3. thank you! Careless of me