TicTacToe Game

/*
Course Title: Algorithm Lab
Course Code: CSE215
Group Name: Semicolon;
Member #01
Jahid Hasan Jiban
ID: 192-15-13117
Member #02
Sahadath Hossen Saykot
ID: 192-15-13106
Member #03
Mainul Islam
ID: 192-15-13053
Aparna Debnath
ID: 192-15-13030
Mushrat Jahan
ID: 192-15-13029
*/

#include<stdio.h>
#include<conio.h>
#include<windows.h>
#include<stdlib.h>
#include<MMsystem.h>

char square[10] = {'o','1','2','3','4','5','6','7','8','9'};
int checkWin();
void drawBoard();

int main(){
    int player = 1, i,choice;
    char mark;
    do {
        drawBoard();
        player = (player%2) ? 1 : 2;
        printf("Player %d, enter the choice: ",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 Option!");
                player--;
                getch();
            }
            i = checkWin();
            player++;

    }while(i == -1);

    drawBoard();
    if(i==1){
        printf("==>Player %d won!",--player);
    }
    else {
        printf("==>Game draw!");
    }
        getch();
        return 0;
}
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;
}

void drawBoard(){
    system("cls");
    printf("\n\n\t Tic Tac Toe \n\n");
    printf("Player1 (X) - Player2 (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");
}