CS60 Project Assignment 1
-------------------------

Due: Oct 10th at Midnight

Two Player TicTacToe
--------------------

The goal of this project is to design and implement a two player tic
tac toe game in C.  The project should exercise working knowledge of
variables, variable arrays, control and loop structures, and
functions.

TicTacToe
---------

TicTacToe is a simple two player game traditionally played on a 3x3
game board with one player 'X' and one player 'O'.  The game board is
laid out as follows:

| _ | _ | _ |
| _ | _ | _ |
| _ | _ | _ |

For simplicity, we can index the board with (x,y) coordinates in the
following way:

| X | _ | _ |
| _ | _ | _ |
| _ | O | _ |

Where the coordinates of 'X' are (0,0) and the coordinates of 'O' are
(2,1).

Players take turns, one move per turn, at placing their symbol on an
empty place on the board (anywhere where there is a '_' character in
the drawings above).  For instance, player 'X', who goes first, could
place their symbol in any space on the first round:

| X | _ | _ |
| _ | _ | _ |
| _ | _ | _ |

or

| _ | _ | _ |
| _ | X | _ |
| _ | _ | _ |

etc.

On the next turn, player 'O' places their symbol on any remaining
empty spaces:

| X | _ | _ |
| _ | _ | O |
| _ | _ | _ |

The game continues until either player 'X' or player 'O' wins, or
there is a draw.  A player wins if they have successfully filled an
entire row, column, or diagonal with their symbol:

| X | X | X |
| O | _ | _ |
| O | _ | _ |

winner: player 'X'

| O | X | X |
| X | O | _ |
| _ | _ | O |

winner: player 'O'

| X | O | O |
| X | _ | _ |
| X | _ | _ |

winner: player 'X'

| X | O | X |
| X | O | X |
| O | X | O |

winner: no one! draw.

Program Requirements
--------------------

The final program must fulfill the following requirements:

- must operate in two modes: player versus player and player versus computer.

	- in player versus player mode, players take turns making a
	  move

	- in player versus computer mode, computer must play tictactoe
	  as player 'O'

	- computer AI can be as simple as making random valid moves

- must correctly detect when either player has won the game and exit
  the program

- must correctly detect a draw and exit the program

- must implement error checking when a new move is inputted, invalid
  moves are reported and the player should be asked to re-enter their
  move.  Invalid moves are:
	- new move is beyond the coordinates of the board
	- new move places the symbol over an existing symbol (cannot
	  make the same move twice and cannot play in a space where
	  the other player has already played)

- must use functions for at least the following operations:
	- drawing the current game board
	- checking the board for a winner
	- checking validity of new moves

- when the program detects a win or draw, the program must report the
winner or the fact that the game is a draw and exit

Turnin
------------

The turnin tag for this assignment is 'project1' and must include the following files:
	- the code itself

	- a typescript showing compilation and execution of the game
	  under the following scenarios:

		- player versus player, player X winning by completing a row

		- player versus player, player O winning by completing
	 	  a column

		- player versus player, no winner showing a draw

		- player versus computer, whomever wins!

		- in at least one scenario, player attempting to make
		  an invalid move by specifying coordinates beyond the
		  edge of the board

		- in at least one scenario, player attempting to make
		  an invalid move by playing in a space already taken
	   	  up by a previous move

	- an optional README file containing any special instructions
	  for the grader

Extra Credit
-------------

For 10 pts of extra credit, the program should be able to be
configured to use an arbitrary sized, symmetric game board.  The size
of the board should be specified using #define directives and should
be symmetric, so 10x10 is a valid size, but 10x11 is not.  Otherwise,
the rules of the game and requirements are the same.  The typescript
for extra credit should show the game being played on a 3x3 board, a
5x5 board, and another sized board, with all of the turnin scenarios
being played out on at least the 5x5 board, and at least one of the
turnin scenarios being played on the 3x3 and other sized boards. HINT:
if you plan on doing the extra credit, start from scratch with
arbitrary sized game boards in mind!  Depending on coding decisions,
it may be difficult to extend a 3x3 tictactoe program to arbitrary
sized boards.

Sample Output
---------------

You program does not have to look exactly like the following output,
but it must at least draw the board to the screen before and after
every move.

[nurmi@localhost sol]$ gcc tictac.c -o tictac
[nurmi@localhost sol]$ ./tictac
0 - player versus player
1 - player versus computer
Please enter game mode (0 or 1): 0
| _ | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 1,1
Player X plays at (1,1)
| _ | _ | _ |
| _ | X | _ |
| _ | _ | _ |
player O: enter a move in x,y coordinates (x,y): 0,0
Player O plays at (0,0)
| O | _ | _ |
| _ | X | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 0,1
Player X plays at (0,1)
| O | X | _ |
| _ | X | _ |
| _ | _ | _ |
player O: enter a move in x,y coordinates (x,y): 2,2
Player O plays at (2,2)
| O | X | _ |
| _ | X | _ |
| _ | _ | O |
player X: enter a move in x,y coordinates (x,y): 2,1
Player X plays at (2,1)
| O | X | _ |
| _ | X | _ |
| _ | X | O |
X wins!
[nurmi@localhost sol]$ ./tictac
0 - player versus player
1 - player versus computer
Please enter game mode (0 or 1): 0
| _ | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 0,0
Player X plays at (0,0)
| X | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
player O: enter a move in x,y coordinates (x,y): 1,1
Player O plays at (1,1)
| X | _ | _ |
| _ | O | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 0,1
Player X plays at (0,1)
| X | X | _ |
| _ | O | _ |
| _ | _ | _ |
player O: enter a move in x,y coordinates (x,y): 0,2
Player O plays at (0,2)
| X | X | O |
| _ | O | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 2,2
Player X plays at (2,2)
| X | X | O |
| _ | O | _ |
| _ | _ | X |
player O: enter a move in x,y coordinates (x,y): 0,2
player O: Illegal move, try again!
| X | X | O |
| _ | O | _ |
| _ | _ | X |
player O: enter a move in x,y coordinates (x,y): 2,0
Player O plays at (2,0)
| X | X | O |
| _ | O | _ |
| O | _ | X |
O wins!
[nurmi@localhost sol]$ ./tictac
0 - player versus player
1 - player versus computer
Please enter game mode (0 or 1): 0
| _ | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 0,0
Player X plays at (0,0)
| X | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
player O: enter a move in x,y coordinates (x,y): 1,0
Player O plays at (1,0)
| X | _ | _ |
| O | _ | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 1,1
Player X plays at (1,1)
| X | _ | _ |
| O | X | _ |
| _ | _ | _ |
player O: enter a move in x,y coordinates (x,y): 2,2
Player O plays at (2,2)
| X | _ | _ |
| O | X | _ |
| _ | _ | O |
player X: enter a move in x,y coordinates (x,y): 0,2
Player X plays at (0,2)
| X | _ | X |
| O | X | _ |
| _ | _ | O |
player O: enter a move in x,y coordinates (x,y): 2,0
Player O plays at (2,0)
| X | _ | X |
| O | X | _ |
| O | _ | O |
player X: enter a move in x,y coordinates (x,y): 2,1
Player X plays at (2,1)
| X | _ | X |
| O | X | _ |
| O | X | O |
player O: enter a move in x,y coordinates (x,y): 0,1
Player O plays at (0,1)
| X | O | X |
| O | X | _ |
| O | X | O |
player X: enter a move in x,y coordinates (x,y): 1,2
Player X plays at (1,2)
| X | O | X |
| O | X | X |
| O | X | O |
Draw!
[nurmi@localhost sol]$ ./tictac
0 - player versus player
1 - player versus computer
Please enter game mode (0 or 1): 1
| _ | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
player X: enter a move in x,y coordinates (x,y): 0,0
Player X plays at (0,0)
| X | _ | _ |
| _ | _ | _ |
| _ | _ | _ |
Player O plays at (2,2)
| X | _ | _ |
| _ | _ | _ |
| _ | _ | O |
player X: enter a move in x,y coordinates (x,y): 1,1
Player X plays at (1,1)
| X | _ | _ |
| _ | X | _ |
| _ | _ | O |
Player O plays at (1,0)
| X | _ | _ |
| O | X | _ |
| _ | _ | O |
player X: enter a move in x,y coordinates (x,y): 2,0
Player X plays at (2,0)
| X | _ | _ |
| O | X | _ |
| X | _ | O |
Player O plays at (0,2)
| X | _ | O |
| O | X | _ |
| X | _ | O |
player X: enter a move in x,y coordinates (x,y): 1,2
Player X plays at (1,2)
| X | _ | O |
| O | X | X |
| X | _ | O |
Player O plays at (2,1)
| X | _ | O |
| O | X | X |
| X | O | O |
player X: enter a move in x,y coordinates (x,y): 0,1
Player X plays at (0,1)
| X | X | O |
| O | X | X |
| X | O | O |
Draw!
[nurmi@localhost sol]$ exit