Tic Tac Toe C++ code

#include <stdio.h>

#include <stdlib.h>

#include <conio.h>

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

int choice, player;

int checkForWin();

void displayBoard();

void markBoard(char mark);

int main()

{

    int gameStatus;

    char mark;

    player = 1;

    do

    {

      displayBoard();

      // change turns

      player = (player % 2) ? 1 : 2;

      // get input

      printf("Player %d, enter a number: ", player);

      scanf("%d", &choice);

      // set the correct character based on player turn

      mark = (player == 1) ? 'X' : 'O';

      // set board based on user choice or invalid choice

      markBoard(mark);

      gameStatus = checkForWin();

      player++;

    }while (gameStatus == -1);

    if (gameStatus == 1)

        printf("==>\aPlayer %d win ", --player);

    else

        printf("==>\aGame draw");

    return 0;

}

/*********************************************

FUNCTION TO RETURN GAME STATUS

1 FOR GAME IS OVER WITH RESULT

-1 FOR GAME IS IN PROGRESS

O GAME IS OVER AND NO RESULT

 **********************************************/

int checkForWin()

{

    int returnValue = 0;

    if (square[1] == square[2] && square[2] == square[3])

    {

        returnValue = 1;

    }

    else if (square[4] == square[5] && square[5] == square[6])

        returnValue = 1;

    else if (square[7] == square[8] && square[8] == square[9])

        returnValue = 1;

    else if (square[1] == square[4] && square[4] == square[7])

        returnValue = 1;

    else if (square[2] == square[5] && square[5] == square[8])

        returnValue = 1;

    else if (square[3] == square[6] && square[6] == square[9])

        returnValue = 1;

    else if (square[1] == square[5] && square[5] == square[9])

        returnValue = 1;

    else if (square[3] == square[5] && square[5] == square[7])

        returnValue = 1;

    else if (square[1] != '1' && square[2] != '2' && square[3] != '3' &&

        square[4] != '4' && square[5] != '5' && square[6] != '6' && square[7]

        != '7' && square[8] != '8' && square[9] != '9')

        returnValue = 0;

    else

        returnValue = -1;

    return returnValue;

}

/*******************************************************************

FUNCTION TO DRAW BOARD OF TIC TAC TOE WITH PLAYERS MARK

 *******************************************************************/

void displayBoard()

{

    system("cls");

    printf("\n\n\tTic Tac Toe\n\n");

    printf("Player 1 (X)  -  Player 2 (O)\n\n\n");

    printf("     |     |     \n");

    printf("  %c  |  %c  |  %c \n", square[1], square[2], square[3]);

    printf("_____|_____|_____\n");

    printf("     |     |     \n");

    printf("  %c  |  %c  |  %c \n", square[4], square[5], square[6]);

    printf("_____|_____|_____\n");

    printf("     |     |     \n");

    printf("  %c  |  %c  |  %c \n", square[7], square[8], square[9]);

    printf("     |     |     \n\n");

}

/***************************************

set the board with the correct character,

x or o in the correct spot in the array

****************************************/

void markBoard(char mark)

{

    if (choice == 1 && square[1] == '1')

        square[1] = mark;

    else if (choice == 2 && square[2] == '2')

        square[2] = mark;

    else if (choice == 3 && square[3] == '3')

        square[3] = mark;

    else if (choice == 4 && square[4] == '4')

        square[4] = mark;

    else if (choice == 5 && square[5] == '5')

        square[5] = mark;

    else if (choice == 6 && square[6] == '6')

        square[6] = mark;

    else if (choice == 7 && square[7] == '7')

        square[7] = mark;

    else if (choice == 8 && square[8] == '8')

        square[8] = mark;

    else if (choice == 9 && square[9] == '9')

        square[9] = mark;

    else

    {

        printf("Invalid move ");

        player--;

        getch();

    }

}