Tic Tac Toe game.c

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>

char board[3][3];
const char PLAYER = 'X';
const char COMPUTER = 'O';

void resetBoard();
void printBoard();
int checkFreeSpaces();
void playerMove();
void computerMove();
char checkWinner();
void printWinner(char);

int main(){
    printf("\n\n");
    printf("****************************************************\n");
    printf("         Welcome to the Tic Tac Toe game!           \n");
    printf("****************************************************\n");
    printf("\n* Instructions \n\n");
    printf("\tPlayer 1 sign = X\n");
    printf("\tPlayer 2 sign = O\n\n");
    char winner = ' ';

    resetBoard();
    while(winner == ' ' && checkFreeSpaces() != 0)
    {
        printBoard();

        playerMove();
        winner = checkWinner();
        if(winner != ' ' || checkFreeSpaces() == 0){
            break;
        }

        computerMove();
        winner = checkWinner();
        if(winner != ' ' || checkFreeSpaces() == 0){
            break;
        }
    }

    printBoard();
    printWinner(winner);

    return 0;
}

void resetBoard(){
    for(int i = 0; i < 3; i++){
        for(int j = 0; j < 3; j++){
            board[i][j] = ' ';
        }
    }
}

void printBoard(){

    printf(" %c | %c | %c \n", board[0][0], board[0][1], board[0][2]);
    printf("---|---|---\n");
    printf(" %c | %c | %c \n", board[1][0], board[1][1], board[1][2]);
    printf("---|---|---\n");
    printf(" %c | %c | %c \n", board[2][0], board[2][1], board[2][2]);
    printf("\n\n");
}

int checkFreeSpaces(){
    int freeSpaces = 9;
    for(int i = 0; i < 3; i++){
        for(int j = 0; j < 3; j++){
            if(board[i][j] != ' '){
                freeSpaces--;
            }
        }
    }
    return freeSpaces;
}

void playerMove(){
    int x;
    int y;

    do{
        printf("Enter row #(1-3): ");
        scanf("%d", &x);
        x--;
        printf("Enter column #(1-3): ");
        scanf("%d", &y);
        y--;
        printf("\n");
        if(board[x][y] !=' '){
            printf("Invalid move! Try again!\n");
            printf("\n");
        }    
        else{
            board[x][y] = PLAYER;
            break;
        }
    } while(board[x][y] != ' ');
}

void computerMove(){
    srand(time(NULL));
    int x;
    int y;

    if(checkFreeSpaces() > 0){
        do{
            x = rand() % 3;
            y = rand() % 3;
        } while(board[x][y] != ' ');
        board[x][y] = COMPUTER;
    }
}

char checkWinner(){
    //check rows
    for(int i = 0; i < 3; i++){
        if(board[i][0] == board[i][1] && board[i][0] == board[i][2]){
            return board[i][0];
        }
    }

    //check columns
    for(int i = 0; i < 3; i++){
        if(board[0][i] == board[1][i] && board[0][i] == board[2][i]){
            return board[0][i];
        }
    }

    //check diagonals
    if(board[0][0] == board[1][1] && board[0][0] == board[2][2]){
        return board[0][0];
    }
    if(board[0][2] == board[1][1] && board[0][2] == board[2][0]){
        return board[0][2];
    }
    return ' ';
}

void printWinner(char winner) {
    if(winner == PLAYER){
        printf("\n\t --- Game Over --- \n");
        printf("  *** Congratulations, You won!! ***\n");
        printf(":: Thanks for playing Tic Tac Toe game! :: \n");
    }
    else if(winner == COMPUTER){
        printf("\n\t --- Game Over --- \n");
        printf("  *** Sorry, you lost. Better luck next time! ***\n");
        printf(":: Thanks for playing Tic Tac Toe game! :: \n");
    }
    else{
        printf("\n\t --- Game Over --- \n");
        printf("  *** It's a tie! ***\n");
        printf(":: Thanks for playing Tic Tac Toe game! :: \n");
    }
}