Is there a decision problem with a time complexity of Ө(n²)?
In other words, I'm looking for a decision problem for which the best known solution has been proven to have a lower bound of N².
I thought about searching for the biggest number in matrix but the problem is that matrix is an input of O(n²) so the solution is linear.
It doesn't need to be known problem, a hypothetical one would suffice as well.
EDIT I looking for a regular programing problem - not a Turing Machine.
It's could be an arrays, strings, graph etc.