Tic-Tac-Toe Game using Java.......

Features - 1.This program always takes constant time for playing a move and       evaluating winning condition.

2.Game can be played on board of any size ,currently I've configured it for max Board size of 10 .

3.Currently only multiplayer mode is implemented ,single player with bot will be implemented soon .

NOTE-  Conventions to play Tic-Tac-Toe game are as follows...
1.When it asked for size of the board enter single digit number for e.g -if you want to play on 3*3 then just enter "3" (without quotes of course) and press "enter".
         
 2.When you want to play a move enter the row and column index of the position separated by a space .
 e.g - If you want to enter a move on first column of first row then just                     enter "1 1" ( without double quotes ) and then press "enter".  

here is the code ...............

       

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.*;

public class TicTacToeProblem {
 static int size;
 static int mode;
 static HashMap < String, ArrayList < String >> player1RowsAndDiagonals = new HashMap < String, ArrayList < String >> (); //to keep track of rows and diagonal formation for player 1 
 static HashMap < String, ArrayList < String >> player2RowsAndDiagonals = new HashMap < String, ArrayList < String >> (); //to keep track of rows and diagonal formation for player 2
 static HashMap < String, ArrayList < String >> player1Columns = new HashMap < String, ArrayList < String >> (); //to keep track of column formation for player 1 
 static HashMap < String, ArrayList < String >> player2Columns = new HashMap < String, ArrayList < String >> (); //to keep track of column formation for player 2 
 static HashSet < String > filledPositions = new HashSet < String > ();

 public static void main(String[] args) throws NumberFormatException,
  IOException {
   BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
   System.out.println("Please enter the size of board in numeral");
   size = Integer.parseInt(br.readLine());

   while ((size > 10) == true) {
    System.out.println("Max size allowed is 10");
    System.out.println("please re enter the size");
    size = Integer.parseInt(br.readLine());
   }
   System.out.println("please enter playing mode number");
   System.out.println("1.two player");
   System.out.println("2.with bot");
   mode = Integer.parseInt(br.readLine());
   while (mode != 1 && mode != 2) {
    System.out.println("Please enter appropriate choice of mode 1 or 2");
    mode = Integer.parseInt(br.readLine());
   }
   if (mode == 1) {
    System.out.println("Initializing Setup..........");
    multiplayer(size);
   } else
    withBot(size);
   br.close();
  }

 public static void multiplayer(int size) throws IOException {
  String[] playerMove = null;
  String move = null;
  int coordinateX;
  int coordinateY;
  int player;
  int secondDiagonalSum = size + 1;
  int maxMoves = size * size;

  for (int i = 1; i <= size; i++) { //here just initializing arrayLists for each rows and each columns for both players
   ArrayList < String > rowList1 = new ArrayList < String > ();
   ArrayList < String > rowList2 = new ArrayList < String > ();
   ArrayList < String > columnList1 = new ArrayList < String > ();
   ArrayList < String > columnList2 = new ArrayList < String > ();
   player1RowsAndDiagonals.put((new Integer(i).toString()), rowList1);
   player2RowsAndDiagonals.put((new Integer(i).toString()), rowList2);
   player1Columns.put((new Integer(i).toString()), columnList1);
   player2Columns.put((new Integer(i).toString()), columnList2);
  }

  ArrayList < String > player1diag1 = new ArrayList < String > (); //here initializing arrayLists to keep track of both the diagonals for both players
  ArrayList < String > player1diag2 = new ArrayList < String > ();
  ArrayList < String > player2diag1 = new ArrayList < String > ();
  ArrayList < String > player2diag2 = new ArrayList < String > ();

  player1RowsAndDiagonals.put("diag1", player1diag1);
  player1RowsAndDiagonals.put("diag2", player1diag2);
  player2RowsAndDiagonals.put("diag1", player2diag1);
  player2RowsAndDiagonals.put("diag2", player2diag2);

  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

  System.out.println("OK,now start playing enter your choices alternatively");

  for (int i = 0; i < maxMoves; i++) {
   if (i % 2 == 0) {
    System.out.println("player 1 turn");
    player = 1;
   } else {
    System.out.println("player 2 turn");
    player = 2;
   }
   move = br.readLine();
   while (filledPositions.contains(move) == true) { //check for already played Move
    System.out.println("this move has been already played please enter another move");
    move = br.readLine();
   }
   filledPositions.add(move);
   playerMove = move.split(" ");
   coordinateX = Integer.parseInt(playerMove[0]);
   coordinateY = Integer.parseInt(playerMove[1]);

   switch (player) {
    case 1:
     if (playerMove[0].equals(playerMove[1])) { //condition for one of the position in diagonal one
      player1RowsAndDiagonals.get("diag1").add(playerMove[1]);
      player1RowsAndDiagonals.get(playerMove[0]).add(playerMove[1]);
      player1Columns.get(playerMove[1]).add(playerMove[0]);

      if ((coordinateX + coordinateY) == secondDiagonalSum) //condition for one of the position in diagonal two 
       player1RowsAndDiagonals.get("diag2").add(playerMove[1]);

      if ((player1Columns.get(playerMove[1]).size() == size) || (player1RowsAndDiagonals.get("diag1").size() == size) || (player1RowsAndDiagonals.get(playerMove[0]).size() == size) || (player1RowsAndDiagonals.get("diag2").size() == size)) {
       System.out.println("Player 1 wins game is finished");
       return;
      }
     } else {
      player1RowsAndDiagonals.get(playerMove[0]).add(playerMove[1]);
      player1Columns.get(playerMove[1]).add(playerMove[0]);

      if ((coordinateX + coordinateY) == secondDiagonalSum)
       player1RowsAndDiagonals.get("diag2").add(playerMove[1]);

      if ((player1Columns.get(playerMove[1]).size() == size) || (player1RowsAndDiagonals.get("diag1").size() == size) || (player1RowsAndDiagonals.get(playerMove[0]).size() == size) || (player1RowsAndDiagonals.get("diag2").size() == size)) {
       System.out.println("Player 1 wins game is finished");
       return;
      }
     }
     break;
    case 2:
     if (playerMove[0].equals(playerMove[1])) {
      player2RowsAndDiagonals.get("diag1").add(playerMove[1]);
      player2RowsAndDiagonals.get(playerMove[0]).add(playerMove[1]);
      player2Columns.get(playerMove[1]).add(playerMove[0]);

      if ((coordinateX + coordinateY) == secondDiagonalSum)
       player2RowsAndDiagonals.get("diag2").add(playerMove[1]);

      if ((player2Columns.get(playerMove[1]).size() == size) || (player2RowsAndDiagonals.get("diag1").size() == size) || (player2RowsAndDiagonals.get(playerMove[0]).size() == size) || (player2RowsAndDiagonals.get("diag2").size() == size)) {
       System.out.println("Player 1 wins game is finished");
       return;
      }
     } else {
      player2RowsAndDiagonals.get(playerMove[0]).add(playerMove[1]);
      player2Columns.get(playerMove[1]).add(playerMove[0]);

      if ((coordinateX + coordinateY) == secondDiagonalSum)
       player2RowsAndDiagonals.get("diag2").add(playerMove[1]);

      if ((player2Columns.get(playerMove[1]).size() == size) || (player2RowsAndDiagonals.get("diag1").size() == size) || (player2RowsAndDiagonals.get(playerMove[0]).size() == size) || (player2RowsAndDiagonals.get("diag2").size() == size)) {
       System.out.println("Player 2 wins game is finished");
       return;
      }
     }
     break;
    default:
     break;
   }
  } //end of loop 
  System.out.println("Match Tie NO one Wins");
 }



 public static void withBot(int size) {
  System.out.println("Working on it, this mode will be added soon till then keep playing multiplayer mode");
  return;
 }
}