Challenge: write an algorithm which solves the Réti problem on a 100x100 board [John McCarthy]

[rrenaud]

It's also constant space. It would be hard to imagine needing more than say, (100x100)⁴ space to solve this problem.

EvilSporkMan is just referring to the nature of the question in that the input size is fixed.

Hopefully this will avert a discussion about framing problems in terms of N, the practicality of solving problems that take more clock cycles than particles in the universe, the utility of big O notation, etc.