tic-tac-toe.cpp

/***********************************************************************
* Program:
*    Lesson 08, Tic-Tac-Toe
* Summary: 
*    This program reads, displays, and writes a Tic-Tac-Toe board
************************************************************************/

#include <iostream>
#include <fstream>
#include <cassert>

#define BOARD_SIZE 3
#define P1_CHAR 'X'
#define P2_CHAR 'O'
#define EMPTY_CHAR '.'

using namespace std;

bool read(         char board[][BOARD_SIZE], const char* fileName);
bool write(  const char board[][BOARD_SIZE], const char* fileName);
void display(const char board[][BOARD_SIZE]);
bool didWin( const char board[][BOARD_SIZE], char turn);

/**********************************************************************
 * Keeps the data and calles the read/display/write functions
 ***********************************************************************/
int main()
{
   char board[BOARD_SIZE][BOARD_SIZE];

   // read the board
   char fileName[256];
   cout << "Enter source filename: ";
   cin  >> fileName;
   if (!read(board, fileName))
   {
      cout << "ERROR: Unable to open file \"" << fileName << "\"\n";
      return 1;
   }

   // display the board
   display(board);

   // write the board to a file
   cout << "Enter destination filename: ";
   cin  >> fileName;
   if (!write(board, fileName))
   {
      cout << "ERROR: Unable to open file \"" << fileName << "\"\n";
      return 1;
   }

   return 0;
}

/**************************************************************
 * READ
 * Read the board from the specified filename
 *************************************************************/
bool read(char board[][BOARD_SIZE], const char* fileName)
{
   assert(*fileName);

   // open the file
   ifstream fin(fileName);
   if (fin.fail())
      return false;

   // read 9 symbols, hopefully they are . X O
   for (int r = 0; r < BOARD_SIZE; r++)
      for (int c = 0; c < BOARD_SIZE; c++)
      {
         fin >> board[r][c];
         assert(!fin.fail());
         assert(board[r][c] == P1_CHAR ||
                board[r][c] == P2_CHAR ||
                board[r][c] == EMPTY_CHAR);
      }

   // close the file
   fin.close();
   return true;
}

/**********************************************************
 * WRITE
 * Write to fileName the board data
 *********************************************************/
bool write(const char board[][BOARD_SIZE], const char* fileName)
{
   assert(fileName[0] != '\0');

   // open the file
   ofstream fout(fileName);
   if (fout.fail())
      return false;

   // write my 9 symbols
   for (int r = 0; r < BOARD_SIZE; r++)
      for (int c = 0; c < BOARD_SIZE; c++)
         fout << board[r][c] << (c == 2 ? '\n' : ' ');

   // close it!
   fout.close();
   cout << "File written\n";
   return true;
}

/*******************************************************
 * DISPLAY
 * Display the contents the the screen
 *****************************************************/
void display(const char board[][BOARD_SIZE])
{
   // loop through each row
   for (int r = 0; r < BOARD_SIZE; r++)
   {
      // only the first row is not preceeded with the --+-- magic
      if (r != 0)
      {
         for (int i = 0; i < BOARD_SIZE; i++)
         {
            cout << "---";
            if (i != 0 && i != BOARD_SIZE - 1)
               cout << '+';
         }
         cout << endl;
      }
      

      // now, on each row, do the column stuff
      for (int c = 0; c < BOARD_SIZE; c++)
      {
         // display a space for the dot
         if (board[r][c] == EMPTY_CHAR)
            cout << "   ";
         else if (board[r][c] == P1_CHAR)
            cout << " " << 'X' << " ";
         else if (board[r][c] == P2_CHAR)
            cout << " " << 'O' << " ";
         else
            // should never get here
            assert(false);

         // end with a | or a newline
         cout << (c == BOARD_SIZE - 1 ? '\n' : '|');
      }
   }

   // display who won
   if (didWin(board, P1_CHAR))
      cout << P1_CHAR << " won!\n";
   if (didWin(board, P2_CHAR))
      cout << P2_CHAR << " won!\n";
   
   return;
}

/********************************************
 * DID WIN
 * Did a given player (determined by the "turn"
 * variable) win the game?
 *******************************************/
bool didWin(const char board[][BOARD_SIZE], char turn)
{
   return false;
}