Finding local maxima in a 2D array

Question

A local maximum in a 2D array can be defined as a value such that all it\'s 4 neighbours are less than or equal to it, ie, for a[i][j] to be a local maximum,

Answer 1

I believe this question can be answered using what is known as adversary arguments, which gives you a lower bound on the number of comparisons.

And in my opinion, you are right.. this would require atleast n^2 comparisons.