% tic-tac-toe PFS March 2007

% initialization
clear
clc
close all
board = zeros(3,3);
% draw a board
figure
plot([.5 3.5],[-1.5 -1.5 ],'k','linewidth',2);
hold on
plot([.5 3.5],[-2.5 -2.5 ],'k','linewidth',2)
plot([1.5 1.5 ],[-.5 -3.5],'k','linewidth',2)
plot([2.5 2.5 ],[-.5 -3.5],'k','linewidth',2)
hold off
axis off

% get first move
move = input('enter player 1 move [r,c] ');
r = move(1);
c = move(2);
board(r,c) = 1;
text(c,-r,'X','horizontalalignment',...
    'center','fontsize',20)

% start loop with second player
for turn = 1:4
    % player 2 next
    move = input('enter player 2 move [r,c] ');
    r = move(1);
    c = move(2);
    board(r,c) = -1;
    text(c,-r,'O','horizontalalignment',...
        'center','fontsize',20)
    % check for victory by O
    result = [ sum(board), sum(board') ];
    result(7) = board(1,1) + board(2,2) + board(3,3);
    result(8) = board(1,3) + board(2,2) + board(3,1);
    if any(result == -3)
        disp('player 2 wins!!')
        break
    end
    
    % repeat for player 1
    move = input('enter player 1 move [r,c] ');
    r = move(1);
    c = move(2);
    board(r,c) = 1;
    text(c,-r,'X','horizontalalignment',...
        'center','fontsize',20)
    % check for victory by X
    result = [ sum(board), sum(board') ];
    result(7) = board(1,1) + board(2,2) + board(3,3);
    result(8) = board(1,3) + board(2,2) + board(3,1);
    if any(result == 3)
        disp('player 1 wins!!')
        break
    end
    
end

% check for draw 
if all(result ~= 3) & (sum(sum(abs(board))) == 9)
    disp('Nobody wins')
end