#include <iostream>
using namespace std;

char board[10] = {'0','1','2','3','4','5','6','7','8','9'};

// Returns either X or O as a char if one is the winner... else (char)0
char checkWin()
{
   if(board[1] == board[2] && board[1] == board[3])
      return board[1];
   if(board[4] == board[5] && board[4] == board[6])
      return board[4];
   if(board[7] == board[8] && board[7] == board[9])
      return board[7];
   if(board[1] == board[4] && board[1] == board[7])
      return board[1];
   if(board[2] == board[5] && board[2] == board[8])
      return board[2];
   if(board[3] == board[6] && board[3] == board[9])
      return board[3];
   if(board[1] == board[5] && board[1] == board[9])
      return board[1];
   if(board[3] == board[5] && board[3] == board[7])
      return board[3];
   return (char)0;
}// End checkWin

void clearBoard()
{
   board[1] = '1';
   board[2] = '2';
   board[3] = '3';
   board[4] = '4';
   board[5] = '5';
   board[6] = '6';
   board[7] = '7';
   board[8] = '8';
   board[9] = '9';
}// End clearBoard

void displayBoard()
{
   cout << "_\b" << board[1] << "|_\b" << board[2] << "|_\b" << board[3] << endl;
   cout << "_\b" << board[4] << "|_\b" << board[5] << "|_\b" << board[6] << endl;
   cout << board[7] << "|" << board[8] << "|" << board[9] << endl;
}// End displayBoard

int getInput()
{
   int move;
   while(true)
   {
      cout << "Please enter a move: ";
      cin >> move;
      if(board[move] != 'X' && board[move] != 'O')
         return move;
      else
         cout << "That move has already been made." << endl;
   }// End while
}// End getInput()
int main()
{
   int choice;
   int winner;
   int turn = 0;
   // Initialize any remaining variables
   while(turn < 9)
   {
      ++turn;
      displayBoard();
      choice = getInput();
      switch(turn % 2)
      {
         case 1:
            board[choice] = 'X';
            break;
         case 0:
            board[choice] = 'O';
            break;
      }// End switch
      if(winner = checkWin())
         break;
   }// End while
   displayBoard();
   switch(winner)
   {
      case 'O':
         cout << "O has won the game." << endl;
         break;
      case 'X':
         cout << "X has won the game." << endl;
         break;
      default:
         cout << "The game was a CAT." << endl;
         break;
   }// End switch
   return 0;
}// End main

#include <iostream>using namespace std;char board[10] = {'0','1','2','3','4','5','6','7','8','9'};// Returns either X or O as a char if one is the winner... else (char)0char checkWin(){  // Looping over an array of "winning combinations" works rather more nicely  // (to avoid repetition). Also, you can get away with returning a boolean,  // with careful design - because the game can only be won by the player who  // just moved.}// As a general comment, if you really *need* "end whatever" comments on your// braces, it's because your functions etc. are too long. ;)void clearBoard(){  // FFS, use a for loop here:  for (int i = 1; i < 10; i++) { board = '0' + i; }}void displayBoard(){   cout << "_\b" << board[1] << "|_\b" << board[2] << "|_\b" << board[3] << endl;   // What are you expecting the \b stuff to do - underline the numbers? It   // might work if you could go back to the 70s and get hold of a teletype...   // you'll probably instead want to draw -'s on a separate line :/}int getInput(){   int move;   while(true)   {      cout << "Please enter a move: ";      cin >> move;      if(board[move] != 'X' && board[move] != 'O')         return move;      else         cout << "That move has already been made." << endl;   }  // You might want to do some checking for the input being a number,  // and for being between 1 and 9? :)}      switch(turn % 2)      {         case 1:            board[choice] = 'X';            break;         case 0:            board[choice] = 'O';            break;      }// End switch// ew ew ew ew ew. Instead:char symbols[] = { 'O', 'X' };board[choice] = symbols[turn % 2];