Tic-Tac-Toe program

#include <stdio.h> #include <conio.h> 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("\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"); } /******************************************************************* END OF PROJECT ********************************************************************/