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

int checkwin(); void board();

int main() { int player = 1, i, choice;

char mark; do { board(); player = (player % 2) ? 1 : 2;

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

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

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(); } i = checkwin();

player++; }while (i == - 1);

board();

if (i == 1) printf("==>\aPlayer %d win ", --player); else printf("==>\aGame draw");

getch();

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 checkwin() { if (square[1] == square[2] && square[2] == square[3]) return 1;

else if (square[4] == square[5] && square[5] == square[6]) return 1;

else if (square[7] == square[8] && square[8] == square[9]) return 1;

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

else if (square[2] == square[5] && square[5] == square[8]) return 1;

else if (square[3] == square[6] && square[6] == square[9]) return 1;

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

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

return 0; else return - 1; }

/******************************************************************* FUNCTION TO DRAW BOARD OF TIC TAC TOE WITH PLAYERS MARK ********************************************************************/

void board() { system("cls"); printf(" \tTic Tac Toe ");

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

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

printf("_____|_____|_____ "); printf(" | | ");

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

printf("_____|_____|_____ "); printf(" | | ");

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

printf(" | | "); }

/******************************************************************* END OF PROJECT ********************************************************************/

Separate the program into multiple header and source (.h and .c) files.