#include <iostream>
using namespace std;

bool checkWinner(char board[][3])
{
     if ((board[0][0] == board[0][1]) && (board[0][1] == board[0][2])) return true; // rows
     else if ((board[1][0] == board[1][1]) && (board[1][1] == board[1][2])) return true;
     else if ((board[2][0] == board[2][1]) && (board[2][1] == board[2][2])) return true;

     else if ((board[0][0] == board[1][0]) && (board[1][0] == board[2][0])) return true; // columns
     else if ((board[0][1] == board[1][1]) && (board[1][1] == board[2][1])) return true;
     else if ((board[0][2] == board[1][2]) && (board[1][2] == board[2][2])) return true;

     else if ((board[0][0] == board[1][1]) && (board[1][1] == board[2][2])) return true; // diagonals
     else if ((board[0][2] == board[1][1]) && (board[1][1] == board[2][0])) return true;

     else return false;
}

void getMove(char board[][3], char playerToGo)
{
     int position;
     int row;
     int column;
     char entry;
     
     cout << endl;
     cout << "Player " << playerToGo << ", please select your position: ";
     cin >> position;
    
     position = position - 1;
     row = position / 3;
     column = position % 3;
     entry = board[row][column];

     while ((entry == 'X') || (entry == 'O'))
     {
          cout << "That position has already been played, choose again: ";
          cin >> position;
     
          position = position - 1;
          row = position / 3;
          column = position % 3;
          entry = board[row][column];
     }

     board[row][column] = playerToGo;
     
}
// not passing in size, as I know explicitly it's 3 by 3
void displayBoard(char board[][3])
{
     int indexOne;
     int indexTwo;

     for (indexOne = 0; indexOne < 3; indexOne++)
     {
          for (indexTwo = 0; indexTwo < 3; indexTwo++)
          {
               cout << board[indexOne][indexTwo];
               if (indexTwo < 2) cout << " | ";
          }
          cout << endl;
          if (indexOne < 2)
          {
               cout << "---------" << endl;;
          }
               
     }
}

int main(int argc, char* argv[])
{
     int numberOfTurns;
     char playerToGo;
     bool winner;

     char board[3][3];

     board[0][0] = '1';
     board[0][1] = '2';
     board[0][2] = '3';
     board[1][0] = '4';
     board[1][1] = '5';
     board[1][2] = '6';
     board[2][0] = '7';
     board[2][1] = '8';
     board[2][2] = '9';


     cout << "Welcome to TicTacToe!" << endl << endl;

     numberOfTurns = 0; 
     winner = false;
     playerToGo = 'X';

     while ((winner == false) && (numberOfTurns < 9))
     {
          displayBoard(board);
          getMove(board, playerToGo);

          winner = checkWinner(board);
          if (winner)
          {
               cout << playerToGo << " WINS!" << endl;
          }
          else
          {
               if (playerToGo == 'X') playerToGo = 'O';
               else playerToGo = 'X';
          }
          
          numberOfTurns = numberOfTurns + 1;
     }

     if ((winner == false) && (numberOfTurns == 9)) 
          cout << "CAT: It's a tie!" << endl;
     
}