Let n be a posititve integer. On a n×n grid there are n2 unit squares and on these we color the sides with blue such that every unit square has exactly one side with blue.
a) Find the maximun number of blue unit sides we can have on the n×n grid.
b) Find the minimun number of blue unit sides we can have on the n×n grid. BoliviaTSTgridsquare gridcombinatorics