connect4

connect4.rb

class String
    def is_i?
       !!(self =~ /^[-+]?[0-9]+$/)
    end
end

class Board
  def initialize(rows,columns)
    @theBoard = Hash.new
    @rows = rows
    @columns  = columns
  end #end initialize
  
  def drawBoard()
    theOutput = ""
    
    (0..@columns-1).each do |k| 
      theOutput+="=#{k}= "
    end
    theOutput+="\n"
      
    (0..@rows-1).each do |i|
      (0..@columns-1).each do |j|
        if(@theBoard[[i,j]]==nil)
          theOutput+="| | "
        else
          theOutput+="|#{@theBoard[[i,j]].piece}| "
        end        
      end
      theOutput+="\n"
    end
    return theOutput
  end #end drawBoard
  
  def addPiece(row,col,piece)
    if(isEmpty(row,col))
      @theBoard[[row,col]] = piece
      return true
    else
      return false
    end
  end #end addPiece
  
  def dropPiece(col,piece)
    row = @rows-1
      until (row<0)
      if(isEmpty(row,col))
        return addPiece(row,col,piece)
      end
      row-=1
    end
    return false
  end
  
  def isEmpty(row,col)
    return withinBounds(row,col) && @theBoard[[row,col]]==nil
  end #end isEmpty
  
  def withinBounds(row,col)
    return row < @rows && col < @columns
  end #end withinBounds
  
  def isFull(row,col)
    return withinBounds(row,col) && @theBoard[[row,col]]!=nil
  end
  
  def boardFull()
    i=0
    while(i<@columns)
      if(@theBoard[[0,i]]==nil)
        return false
      end
      i+=1
    end
    return true
  end
  
  def stepThrough(direction,current,i,j)
     k=0
     toReturn=true
     while(k<4)
       if(direction=='up')
         if(!current.compare(@theBoard[[i+k,j]]))
           toReturn=false
           break
         end
         k+=1
       end
       if(direction=='right')
          if(!current.compare(@theBoard[[i,j+k]]))
            toReturn=false
            break
          end
          k+=1
        end
         if(direction=='diagright')
            if(!current.compare(@theBoard[[i-k,j+k]]))
              toReturn=false
              break
            end
            k+=1
          end
          if(direction=='diagleft')
              if(!current.compare(@theBoard[[i-k,j-k]]))
                toReturn=false
                break
              end
              k+=1
            end
     end
     return toReturn
  end
  
  def fourConnected()
    toReturn = []
    (0..@rows-1).each do |i|
      (0..@columns-1).each do |j|
        if(isFull(i,j))
          current = @theBoard[[i,j]]
         if(isFull(i+3,j)) #up
            if(stepThrough('up',current,i,j))
              return true
            end
         end
         if(isFull(i,j+3)) #right
            if(stepThrough('right',current,i,j))
              return true
            end
         end
          if(isFull(i-3,j+3)) #diagright
             if(stepThrough('diagright',current,i,j))
               return true
             end
          end
          if(isFull(i-3,j-3)) #diagleft
             if(stepThrough('diagleft',current,i,j))
               return true
             end
          end
        end
        
      end
    end
    
    return false
  end
end

class Piece
  
  def initialize(color,piece='x')
    @color  = color
    @piece  = piece
  end
  
  def compare(otherPiece)
    if(otherPiece!=nil)
      return otherPiece.color == @color
    end
    return false
  end
  
  def piece
    @piece
  
  end
  
  def color
    @color
  
  end

end

class Game

  def initialize()
    @players  = 2
    @turn     = Random.rand(2)
    @board    = Board.new(10,10)
    @pieces   = [Piece.new("red","X"),Piece.new("black","O")]
    gameLoop()
  end
  
  def clearScreen()
    puts "\e[H\e[2J"
  end
  
  def getInput()
    col = ""
    while(1)
      puts  "\nENTER A COLUMN TO DROP YOUR PIECE: "
      STDOUT.flush
      col = gets.chomp
      if(col.is_i?&&col.to_i>=0)
        break
      else
        puts "\n***ERROR IN INPUT TRY AGAIN***"
      end
    end
    return col.to_i
  end
  
  def gameOver()
    return @board.boardFull() || @board.fourConnected()
  end
  
  def gameLoop
    while(!gameOver())
      clearScreen()
      puts "PLAYER #{@turn+1} TURN\n\n"
      puts  @board.drawBoard()
      if(@board.dropPiece(getInput(),@pieces[@turn]))
        @turn = (@turn+1)%(@players)
      else
        puts "\n***ERROR IN DROPPING PIECE***"
      end
    end
    clearScreen()
    puts "GAME OVER"
    puts "PLAYER #{@turn+1} WINS!!!\n\n"
    
    puts  @board.drawBoard()
    
  end
  
end


newGame = Game.new()