/**
 * Matt Kretchmar
 * February 28, 2006
 * ConnectFour.java
 * This program implements a version of the connect four board game.  Two
 * players alternate placing chips in columns of a square board attempting to obtain 
 * four in a row of their color.  Player 1 (white chips) goes first while,
 * player 2 has black chips.  A player must get four in a row horizontally
 * or vertically (diagonal does not count).  When placing chips in a column,
 * the new chip must "fall" to the bottom of the column.  
 */ 

import java.util.Scanner;

class ConnectFour
{
    final static int ROWS = 6;      // board has 6 rows
    final static int COLS = 6;      // and 6 columns
    
    public static void main ( String [] args )
    {
        Scanner keyboard = new Scanner(System.in);
        int  board[][] = new int[ROWS][COLS];
        int i, j;
        
        int moves = 0;
        // Initialize the board for a new game
        for ( i = 0; i < ROWS; i++ )
        {
            for ( j = 0; j < COLS; j++ )
            {
                board[i][j] = 0;
            }
        }
        
        //============================================
        // repeat until a player wins a game
        //============================================
        boolean player1Wins = false;
        boolean player2Wins = false;
        int turn = 1;  // player 1 goes first
        while ( !player1Wins && !player2Wins && moves < ROWS*COLS)
        {
            // Display the board
            System.out.print("+-");
            for ( j = 0; j < COLS; j++ )
                System.out.print((j+1) + "-");
            System.out.println("+");
            
            for ( i = ROWS-1; i >= 0; i-- )
            {
                System.out.print("| ");
                for ( j = 0; j < COLS; j++ )
                {
                    char c = ' ';
                    switch ( board[i][j] )
                    {
                        case 0 : c = ' '; break;
                        case 1 : c = 'w'; break;
                        case 2 : c = 'b'; break;
                    }
                    System.out.print(c + " ");
                }
                System.out.println("|");
            }
            System.out.print("+-");
            for ( j = 0; j < COLS; j++ )
                System.out.print("--");
            System.out.println("+");
            
            // Prompt for an input
            int column;
            do
            {
                System.out.println("Player " + turn + " enter column to play a move: ");
                column = keyboard.nextInt() - 1;
                if ( column < 0 || column >= COLS || board[ROWS-1][column] > 0 )
                    System.out.println("Invalid column or column already full, try another\n");
            } while ( column < 0 || column >= COLS || board[ROWS-1][column] > 0 );
            moves++;
            
            // put move into right row of indicated column
            i = 0;
            while ( board[i][column] > 0 )
                i++;
            board[i][column] = turn;
            
            
            // next player's turn
            if ( turn == 1 )
                turn = 2;
            else
                turn = 1;
            
            //=================================
            // now test for winner
            //=================================
            
            // test each row to see if there are four in a row
            for ( i = 0; i < ROWS; i++ )
            {
                int current = board[i][0];
                j = 1;
                int count = 1;
                while ( j < COLS )
                {
                    if ( board[i][j] == current && board[i][j] != 0 )
                    {
                        count++;
                    }
                    else
                    {
                        current = board[i][j];
                        count = 1;
                    }
                    if ( count == 4 )
                    {
                        if ( current == 1 )
                            player1Wins = true;
                        else
                            player2Wins = true;
                    }
                    j++;
                }
            }
            
            // test each col to see if there are four in a row
            for ( j = 0; j < COLS; j++ )
            {
                int current = board[0][j];
                i = 1;
                int count = 1;
                while ( i < ROWS )
                {
                    if ( board[i][j] == current && board[i][j] != 0 )
                    {
                        count++;
                    }
                    else
                    {
                        current = board[i][j];
                        count = 1;
                    }
                    if ( count == 4 )
                    {
                        if ( current == 1 )
                            player1Wins = true;
                        else
                            player2Wins = true;
                    }
                    i++;
                }
            }
        }
        
        // draw board once more
        System.out.print("+-");
        for ( j = 0; j < COLS; j++ )
            System.out.print((j+1) + "-");
        System.out.println("+");
        
        for ( i = ROWS-1; i >= 0; i-- )
        {
            System.out.print("| ");
            for ( j = 0; j < COLS; j++ )
            {
                char c = ' ';
                switch ( board[i][j] )
                {
                    case 0 : c = ' '; break;
                    case 1 : c = 'w'; break;
                    case 2 : c = 'b'; break;
                }
                System.out.print(c + " ");
            }
            System.out.println("|");
        }
        System.out.print("+-");
        for ( j = 0; j < COLS; j++ )
            System.out.print("--");
        System.out.println("+");
        
        // Now declare a winner
        if ( player1Wins )
            System.out.println("Player 1 wins!!!");
        else if ( player2Wins )
            System.out.println("Player 2 wins!!!");
        else
            System.out.println("Tie game.");
        
    }
}