billsSolidity.sol

contract TicTacToe {
    address player_one;
    address player_two;
    address public next_player;
    address public winner;
    mapping (uint => address) game_board;
    uint total_moves;
    bool public game_in_progress;

    /// @notice Creates a tictactoe game for first player (first up) and second player
    /// to be played on a gameboard numbered one through nine, horizontally first.
    /// row 1: 1 2 3
    /// row 2: 4 5 6
    /// row 3: 7 8 9
    /// @param _player_one address of first player
    /// @param _player_two address of second player
    function TicTacToe(address _player_one, address _player_two) {
        // set player one
        player_one = _player_one;

        // set player two
        player_two = _player_two;

        // set next player state
        next_player = player_one;

        // set number of moves state
        total_moves = 0;

        // set game in progress state
        game_in_progress = true;
    }

    /// @notice Attempts to place a move on the game board at a player's request.
    function move(uint8 square) returns(bool sufficient) {
        // verify game is in progress
        if (!game_in_progress) return false;

        // verify correct player is attempting a move
        if (next_player != msg.sender) return false;

        // verify requested square is valid
        if ((square < 1) || (square > 9)) return false;

        // verify square is not consumed
        if ((game_board[square] == player_one) || 
            (game_board[square] == player_two)) {
                return false;
        }

        // allow the player to make the move
        game_board[square] = msg.sender;

        // increment number of game moves
        total_moves++;

        // determine if game is complete
        bool completed = isGameComplete(square);

        if (completed) {
            game_in_progress = false;
            return true;
        }

        // change player state
        if (msg.sender == player_one) {
            next_player = player_two;
        }
        if (msg.sender == player_two) {
            next_player = player_one;
        }
        return true;
    }
	
    /// @notice Determine if game is complete and if not a draw set the winner
    function isGameComplete(uint8 square) returns(bool complete) {
        // determine player 
        address player = game_board[square];

        // upper left move
        if (square == 1) {
            // top row
            if ((game_board[2] == player) && (game_board[3] == player)) {
                winner = player;
                return true;
            }	
            // left column
            if ((game_board[4] == player) && (game_board[7] == player)) {
                winner = player;
                return true;
            }	
            // diagonal 
            if ((game_board[5] == player) && (game_board[9] == player)) {
                winner = player;
                return true;
            }	
        }

        // upper mid move
        if (square == 2) {
            // top row
            if ((game_board[1] == player) && (game_board[3] == player)) {
                winner = player;
                return true;
            }	
            // mid column
            if ((game_board[5] == player) && (game_board[8] == player)) {
                winner = player;
                return true;
            }	
        }

        // upper right move
        if (square == 3) {
            // top row
            if ((game_board[1] == player) && (game_board[2] == player)) {
                winner = player;
                return true;
            }	
            // right column
            if ((game_board[6] == player) && (game_board[9] == player)) {
                winner = player;
                return true;
            }	
            // diagonal 
            if ((game_board[5] == player) && (game_board[7] == player)) {
                winner = player;
                return true;
            }	
        }

        // mid left move
        if (square == 4) {
            // middle row
            if ((game_board[5] == player) && (game_board[6] == player)) {
                winner = player;
                return true;
            }	
            // left column
            if ((game_board[1] == player) && (game_board[7] == player)) {
                winner = player;
                return true;
            }	
        }

        // center move
        if (square == 5) {
            // middle row
            if ((game_board[4] == player) && (game_board[6] == player)) {
                winner = player;
                return true;
            }	
            // mid column
            if ((game_board[2] == player) && (game_board[8] == player)) {
                winner = player;
                return true;
            }	
            // diagonal
            if ((game_board[1] == player) && (game_board[9] == player)) {
                winner = player;
                return true;
            }	
        }

        // mid right move
        if (square == 6) {
            // middle row
            if ((game_board[4] == player) && (game_board[5] == player)) {
                winner = player;
                return true;
            }	
            // right column
            if ((game_board[3] == player) && (game_board[9] == player)) {
                winner = player;
                return true;
            }	
        }

        // lower left move
        if (square == 7) {
            // bottom row
            if ((game_board[8] == player) && (game_board[9] == player)) {
                winner = player;
                return true;
            }	
            // left column
            if ((game_board[1] == player) && (game_board[4] == player)) {
                winner = player;
                return true;
            }	
            // diagonal 
            if ((game_board[5] == player) && (game_board[3] == player)) {
                winner = player;
                return true;
            }	
        }

        // lower mid move
        if (square == 8) {
            // bottom row
            if ((game_board[7] == player) && (game_board[9] == player)) {
                winner = player;
                return true;
            }	
            // mid column
            if ((game_board[2] == player) && (game_board[5] == player)) {
                winner = player;
                return true;
            }	
        }

        // lower right move
        if (square == 9) {
            // bottom row
            if ((game_board[7] == player) && (game_board[8] == player)) {
                winner = player;
                return true;
            }	
            // right column
            if ((game_board[3] == player) && (game_board[6] == player)) {
                winner = player;
                return true;
            }	
            // diagonal 
            if ((game_board[1] == player) && (game_board[5] == player)) {
                winner = player;
                return true;
            }	
        }

        // check for a draw
        if (total_moves >= 9) return true;

        // if we get to this point then game is still in progress
        return false;
    }
}