GCJ 2013 - Tic-Tac-Toe-Tomek

TicTacToe.java

package com.bchetty.gcj2013;

/**
 *
 * @author Babji Prashanth, Chetty
 */
public class TicTacToe {
    //Possible 'X' winning combination strings
    public static final String xWin1 = "XXXX";
    public static final String xWin2 = "XXXT";
    public static final String xWin3 = "XXTX";
    public static final String xWin4 = "XTXX";
    public static final String xWin5 = "TXXX";
    
    //Possible 'O' winning combination strings
    public static final String oWin1 = "OOOO";
    public static final String oWin2 = "OOOT";
    public static final String oWin3 = "OOTO";
    public static final String oWin4 = "OTOO";
    public static final String oWin5 = "TOOO";
    
    /**
     * This method returns the status of the game
     * 
     * @param board
     * @return 
     */
    private String getStatusQuo(String[] board) {        
        boolean notComplete = false;
        
        //Loop through all rows
        for(int i=0;i<4;i++) {
            if(board[i].indexOf(".") < 0) {
                String res1 = check(board[i]);
                if(res1 != null) {
                    return res1;
                }                
            } else {
                notComplete = true;                
            }            
            
            //Loop through all columns
            if(i==0) {
                for(int j=0;j<4;j++) {
                    String col = board[0].charAt(j) + "" + board[1].charAt(j) + "" + board[2].charAt(j) + "" +
                            board[3].charAt(j);
                    if(col.indexOf(".") < 0) {
                        String res2 = check(col);
                        if(res2 != null) {
                            return res2;
                        }                        
                    } else {
                        notComplete = true;                         
                    }
                    
                    //Construct the first diagonal and check it
                    if(j == 0) {
                        String diag1 = board[0].charAt(0) + "" + board[1].charAt(1) + "" + board[2].charAt(2) + "" +
                            board[3].charAt(3);
                        
                        if(diag1.indexOf(".") < 0) {
                            String res3 = check(diag1);
                            if(res3 != null) {
                               return res3;
                            }                       
                        } else {
                            notComplete = true;                         
                        }
                    }
                    
                    //Construct the second diagonal and check it
                    if(j == 3) {
                        String diag2 = board[0].charAt(3) + "" + board[1].charAt(2) + "" + board[2].charAt(1) + "" +
                            board[3].charAt(0);
                        
                        if(diag2.indexOf(".") < 0) {
                            String res4 = check(diag2);
                            if(res4 != null) {
                                return res4;
                            }                       
                        } else {
                            notComplete = true;                         
                        }
                    }
                }       
            }
        }
        
        return notComplete ? "Game has not completed" : "Draw";
    }
    
    /**
     * 
     * @param str
     * @return 
     */
    private String check(String str) {
        if(str.equals(xWin1) || str.equals(xWin2) || str.equals(xWin3) || 
                str.equals(xWin4) || str.equals(xWin5)) {
            return "X won";
        }
        if(str.equals(oWin1) || str.equals(oWin2) || str.equals(oWin3) || 
                str.equals(oWin4) || str.equals(oWin5)) {
            return "O won";
        }
        
        return null;
    }
}