Modeling the data structure

Coming back to the old adage, data structures, not algorithms, are central to writing good programs. Therefore, it is important that we spend some time defining the data structure.

The key data that the model needs to record is the position of the chess pieces on the chessboard. Accordingly, we first need a way to define these locations and a unique way to identify the chess pieces. Let's first agree to the naming conventions that we will stick to in the program.

Convention on naming chess pieces

Every chess piece is identified by a single letter (pawn = p, knight = n (yes knight with an n!), bishop = b, rook = r, queen = q, and king = k).

The white chess pieces are represented by uppercase...