Here is the code for you: import java.util.Scanner; import java.util.Random; public class TicTacToeGame { static char[] [] board = new char[3][3]; static Scanner input=new Scanner(System.in); //Object of Stats class to maintain statistics static Stats stat = new Stats(); /** * Prints the TicTacToe board * @param arr: The board so far */ public static void printBoard(char [][] arr){ System.out.println(); for (int i=0; i<3; i++) { for (int j=0; j<3; j++) { System.out.print(arr[i][j]); if(j!=2) //Print the | for readable output System.out.print(\" \" + \"|\" + \" \"); } System.out.println(); if(i!=2) { System.out.print(\"_ _ _ \"); // Print _ for readability System.out.println();; } } } /** * Clear the TicTacToe board before starting a new game * @param arr: The board so far */ public static void clearBoard(char [][] arr){ for (int i=0; i<3; i++) { for (int j=0; j<3; j++) { arr[i][j]=\' \'; } } } /** Determines if the player with the specified token wins * * @param symbol: Specifies whether the player is X or O * @return true if player has won, false otherwise */ public static boolean isWon(char symbol) { for (int i = 0; i < 3; i++) //horizontal if (board[i][0] == symbol && board[i][1] == symbol && board[i][2] == symbol) { return true; } //TODO!!! Also check for vertical and the two diagonals for (int i = 0; i < 3; i++) //vertical if (board[0][i] == symbol && board[1][i] == symbol && board[2][i] == symbol) { return true; } //Leading diagonal if (board[0][0] == symbol && board[1][1] == symbol && board[2][2] == symbol) { return true; } //Trailing diagonal if (board[0][2] == symbol && board[1][1] == symbol && board[2][0] == symbol) { return true; } return false; } /** Determines if the cell is occupied * * @param row: Row of the cell to be checked * @param col: Column of the cell to be checked * @return true if the cell is occupied, false otherwise */ public static boolean isOccupied(int row, int col){ if (board[row][col]!=\' \') return false; else return true; } /** Determines who starts the game */ public static int whoStarts(){ //TODO: Randomly chooses between 0 and 1 and returns the choice return (int)(Math.random() + 0.5 ); } /** takes care of the human\'s move * 1. Prompt for a cell, then column * 2. Puts a symbol (X or O) on the board * 3. Prints the updated board * 4. If a human wins: prints, updates stats and returns true * 5. If not a win yet, returns false */ public static boolean humanTurn(char symbol){ //Prompt for a cell. User must enter //row and column with a space in between. System.out.print(\"\ \ Enter your move: (row column): \" ); int row = input.nextInt(); int col = input.nextInt(); //TODO!!! Mark user move in the board, print //the board and check if user has won! board[row][col] = symbol; printBoard(board); if(isWon(symbol)) return true; return false; } /** takes care of the computer\'s move * 1. Generates numbers until finds an empty cell * 2. Puts a symbol (X or O) on the board * 3. Prints the updated board * 4. If a comp .

1. Here is the code for you:
import java.util.Scanner;
import java.util.Random;
public class TicTacToeGame {
static char[] [] board = new char[3][3];
static Scanner input=new Scanner(System.in);
//Object of Stats class to maintain statistics
static Stats stat = new Stats();
/**
* Prints the TicTacToe board
* @param arr: The board so far
*/
public static void printBoard(char [][] arr){
System.out.println();
for (int i=0; i<3; i++)
{
for (int j=0; j<3; j++)
{
System.out.print(arr[i][j]);
if(j!=2)
//Print the | for readable output
System.out.print(" " + "|" + " ");
}
System.out.println();
if(i!=2) {
System.out.print("_ _ _ "); // Print _ for readability
System.out.println();;
}
}
}
/**
* Clear the TicTacToe board before starting a new game
* @param arr: The board so far

2. */
public static void clearBoard(char [][] arr){
for (int i=0; i<3; i++)
{
for (int j=0; j<3; j++)
{
arr[i][j]=' ';
}
}
}
/** Determines if the player with the specified token wins
*
* @param symbol: Specifies whether the player is X or O
* @return true if player has won, false otherwise
*/
public static boolean isWon(char symbol) {
for (int i = 0; i < 3; i++) //horizontal
if (board[i][0] == symbol
&& board[i][1] == symbol
&& board[i][2] == symbol) {
return true;
}
//TODO!!! Also check for vertical and the two diagonals
for (int i = 0; i < 3; i++) //vertical
if (board[0][i] == symbol
&& board[1][i] == symbol
&& board[2][i] == symbol) {
return true;
}
//Leading diagonal
if (board[0][0] == symbol
&& board[1][1] == symbol
&& board[2][2] == symbol) {
return true;

3. }
//Trailing diagonal
if (board[0][2] == symbol
&& board[1][1] == symbol
&& board[2][0] == symbol) {
return true;
}
return false;
}
/** Determines if the cell is occupied
*
* @param row: Row of the cell to be checked
* @param col: Column of the cell to be checked
* @return true if the cell is occupied, false otherwise
*/
public static boolean isOccupied(int row, int col){
if (board[row][col]!=' ') return false;
else return true;
}
/** Determines who starts the game
*/
public static int whoStarts(){
//TODO: Randomly chooses between 0 and 1 and returns the choice
return (int)(Math.random() + 0.5 );
}
/** takes care of the human's move
* 1. Prompt for a cell, then column
* 2. Puts a symbol (X or O) on the board
* 3. Prints the updated board
* 4. If a human wins: prints, updates stats and returns true
* 5. If not a win yet, returns false */
public static boolean humanTurn(char symbol){

4. //Prompt for a cell. User must enter
//row and column with a space in between.
System.out.print(" Enter your move: (row column): " );
int row = input.nextInt();
int col = input.nextInt();
//TODO!!! Mark user move in the board, print
//the board and check if user has won!
board[row][col] = symbol;
printBoard(board);
if(isWon(symbol))
return true;
return false;
}
/** takes care of the computer's move
* 1. Generates numbers until finds an empty cell
* 2. Puts a symbol (X or O) on the board
* 3. Prints the updated board
* 4. If a comp wins: prints, updates stats and returns true
* 5. If not a win yet, returns false */
public static boolean compTurn(char symbol) {
int row, col;
// TODO!!!
//Choose a random row (0-2) and column (0-2)
row = new Random().nextInt(3);
col = new Random().nextInt(3);
//Check if the randomly chosen cell is occupied. Keep choosing
//until an empty cell is found
while(isOccupied(row, col))
{
row = new Random().nextInt(3);
col = new Random().nextInt(3);

5. }
System.out.println(" My Move is: "+row+" "+ col);
//Mark the move, print the board and check if computer won
board[row][col] = symbol;
printBoard(board);
if(isWon(symbol))
return true;
return false;
}
/** If human goes first:
* We have 9 moves in total (max). 8 moves will be in a loop
* and the last human move is outside of the loop:
* 1. human goes first, with a X
* 2. If the returned value is true (human won), then boolean flag=true
* and we break out of the loop. done indicates that the game is over.
* 3. If the game is not over, then it is computer's turn.
* 4. If the returned value is true (comp won), then boolean flag=true
* and we break out of the loop. done indicates that the game is over
* 5. Repeat the two steps above 3 more times.
* 6. If the done is still false, then a human performs one more move and
* we check if the move led to the win or tie.
* */
public static void humanFirst(){
boolean done=false;
for (int i=0; i<4; i++) {
if (humanTurn('X')) {
done=true;
break;
}
if (compTurn('O')){
done=true;
break;
}

6. } //end of for loop;
if (!done){
if (!humanTurn('X')) {
System.out.println(" A tie!");
stat.incrementTies();
}
}
}
/**
* Same logic as above, only the first computer's move happens before
* the loop. We do not need to check for winning combination here, since
* comp can't win after one move.
* After the loop we check if the game is done. If not, report a tie and
* update statistics.
*/
public static void compFirst(){
//TODO: Complete the method
boolean done=false;
for (int i=0; i<4; i++) {
if (compTurn('X')) {
done=true;
break;
}
if (humanTurn('O')){
done=true;
break;
}
} //end of for loop;
if (!done){
if (!compTurn('X')) {
System.out.println(" A tie!");
stat.incrementTies();
}

7. }
}
public static void main(String[] args) {
// input from the user, if he wants to play another game
String playAgain="";
// input from the user, if he wants to clear stats
String clearStats="";
do { //play until 'n' is pressed
clearBoard(board); //clear the baord
//Generate Random Assignment, determines who goes first;
int move = whoStarts();
if (move == 0) {
System.out.println(" I start first. I choose X and you get 0");
computerFirst();
}
else{
System.out.println(" You start first. You get X and I get 0");
humanFirst();
}
//TODO!!!
//Print statistics and ask if a user wants to repeat a game
stat.printStat();
System.out.print("Do you want to play again: ");
playAgain = input.next();
// If user enters 'y', ask to clear statistics
if(playAgain.charAg(0) == 'y')
{
System.out.print("Do you want to clear statistics: ");
clearStats = input.next();
if(clearStats.charAt(0) == 'y')
stats.clearStatistics();

8. }
// if user enters 'y', clear statistics and restart the game
//If user enters 'n', continue without clearing
// //If user enters 'n', quit the game
} while(playAgain.charAt(0)!='n'); //done with the outer loop
System.out.println(" Bye, see you later!");
}
}
Solution
Here is the code for you:
import java.util.Scanner;
import java.util.Random;
public class TicTacToeGame {
static char[] [] board = new char[3][3];
static Scanner input=new Scanner(System.in);
//Object of Stats class to maintain statistics
static Stats stat = new Stats();
/**
* Prints the TicTacToe board
* @param arr: The board so far
*/
public static void printBoard(char [][] arr){
System.out.println();
for (int i=0; i<3; i++)
{
for (int j=0; j<3; j++)
{
System.out.print(arr[i][j]);
if(j!=2)
//Print the | for readable output

9. System.out.print(" " + "|" + " ");
}
System.out.println();
if(i!=2) {
System.out.print("_ _ _ "); // Print _ for readability
System.out.println();;
}
}
}
/**
* Clear the TicTacToe board before starting a new game
* @param arr: The board so far
*/
public static void clearBoard(char [][] arr){
for (int i=0; i<3; i++)
{
for (int j=0; j<3; j++)
{
arr[i][j]=' ';
}
}
}
/** Determines if the player with the specified token wins
*
* @param symbol: Specifies whether the player is X or O
* @return true if player has won, false otherwise
*/
public static boolean isWon(char symbol) {
for (int i = 0; i < 3; i++) //horizontal
if (board[i][0] == symbol
&& board[i][1] == symbol
&& board[i][2] == symbol) {
return true;

10. }
//TODO!!! Also check for vertical and the two diagonals
for (int i = 0; i < 3; i++) //vertical
if (board[0][i] == symbol
&& board[1][i] == symbol
&& board[2][i] == symbol) {
return true;
}
//Leading diagonal
if (board[0][0] == symbol
&& board[1][1] == symbol
&& board[2][2] == symbol) {
return true;
}
//Trailing diagonal
if (board[0][2] == symbol
&& board[1][1] == symbol
&& board[2][0] == symbol) {
return true;
}
return false;
}
/** Determines if the cell is occupied
*
* @param row: Row of the cell to be checked
* @param col: Column of the cell to be checked
* @return true if the cell is occupied, false otherwise
*/
public static boolean isOccupied(int row, int col){
if (board[row][col]!=' ') return false;
else return true;
}
/** Determines who starts the game
*/

11. public static int whoStarts(){
//TODO: Randomly chooses between 0 and 1 and returns the choice
return (int)(Math.random() + 0.5 );
}
/** takes care of the human's move
* 1. Prompt for a cell, then column
* 2. Puts a symbol (X or O) on the board
* 3. Prints the updated board
* 4. If a human wins: prints, updates stats and returns true
* 5. If not a win yet, returns false */
public static boolean humanTurn(char symbol){
//Prompt for a cell. User must enter
//row and column with a space in between.
System.out.print(" Enter your move: (row column): " );
int row = input.nextInt();
int col = input.nextInt();
//TODO!!! Mark user move in the board, print
//the board and check if user has won!
board[row][col] = symbol;
printBoard(board);
if(isWon(symbol))
return true;
return false;
}
/** takes care of the computer's move
* 1. Generates numbers until finds an empty cell
* 2. Puts a symbol (X or O) on the board
* 3. Prints the updated board
* 4. If a comp wins: prints, updates stats and returns true
* 5. If not a win yet, returns false */
public static boolean compTurn(char symbol) {

12. int row, col;
// TODO!!!
//Choose a random row (0-2) and column (0-2)
row = new Random().nextInt(3);
col = new Random().nextInt(3);
//Check if the randomly chosen cell is occupied. Keep choosing
//until an empty cell is found
while(isOccupied(row, col))
{
row = new Random().nextInt(3);
col = new Random().nextInt(3);
}
System.out.println(" My Move is: "+row+" "+ col);
//Mark the move, print the board and check if computer won
board[row][col] = symbol;
printBoard(board);
if(isWon(symbol))
return true;
return false;
}
/** If human goes first:
* We have 9 moves in total (max). 8 moves will be in a loop
* and the last human move is outside of the loop:
* 1. human goes first, with a X
* 2. If the returned value is true (human won), then boolean flag=true
* and we break out of the loop. done indicates that the game is over.
* 3. If the game is not over, then it is computer's turn.
* 4. If the returned value is true (comp won), then boolean flag=true
* and we break out of the loop. done indicates that the game is over
* 5. Repeat the two steps above 3 more times.
* 6. If the done is still false, then a human performs one more move and
* we check if the move led to the win or tie.

13. * */
public static void humanFirst(){
boolean done=false;
for (int i=0; i<4; i++) {
if (humanTurn('X')) {
done=true;
break;
}
if (compTurn('O')){
done=true;
break;
}
} //end of for loop;
if (!done){
if (!humanTurn('X')) {
System.out.println(" A tie!");
stat.incrementTies();
}
}
}
/**
* Same logic as above, only the first computer's move happens before
* the loop. We do not need to check for winning combination here, since
* comp can't win after one move.
* After the loop we check if the game is done. If not, report a tie and
* update statistics.
*/
public static void compFirst(){
//TODO: Complete the method
boolean done=false;
for (int i=0; i<4; i++) {
if (compTurn('X')) {

14. done=true;
break;
}
if (humanTurn('O')){
done=true;
break;
}
} //end of for loop;
if (!done){
if (!compTurn('X')) {
System.out.println(" A tie!");
stat.incrementTies();
}
}
}
public static void main(String[] args) {
// input from the user, if he wants to play another game
String playAgain="";
// input from the user, if he wants to clear stats
String clearStats="";
do { //play until 'n' is pressed
clearBoard(board); //clear the baord
//Generate Random Assignment, determines who goes first;
int move = whoStarts();
if (move == 0) {
System.out.println(" I start first. I choose X and you get 0");
computerFirst();
}
else{
System.out.println(" You start first. You get X and I get 0");
humanFirst();
}

15. //TODO!!!
//Print statistics and ask if a user wants to repeat a game
stat.printStat();
System.out.print("Do you want to play again: ");
playAgain = input.next();
// If user enters 'y', ask to clear statistics
if(playAgain.charAg(0) == 'y')
{
System.out.print("Do you want to clear statistics: ");
clearStats = input.next();
if(clearStats.charAt(0) == 'y')
stats.clearStatistics();
}
// if user enters 'y', clear statistics and restart the game
//If user enters 'n', continue without clearing
// //If user enters 'n', quit the game
} while(playAgain.charAt(0)!='n'); //done with the outer loop
System.out.println(" Bye, see you later!");
}
}