Krish - you could consider using a cell array to represent the characters in your board. For example,
n = 12;
board = cell(n+1,n+1);
% initialize the board
for u=1:n+1
for v=1:n+1
if u==1
if v<=n
board{u,v+1} = v;
board{v+1,u} = v;
end
elseif v==1
% do nothing
else
board{u,v} = 'x';
end
end
end
would create a board similar to what you are requesting. I noticed that you tagged your question with "GUI". Were you hoping to create some sort of GUI with the above board embedded in it?
