You must complete the code so that it works as follows:

$1.$Once the user has used the Left Mouse Key to create at least one path from one side of the screen to the other, the user should then be able to Right Click the mouse on a yellow cell on the left most side of the screen.

$2.$The program should then search using the recursive search$()$ function to find a path to the right side of the screen following one of the user$$s created paths.

$3.$Each cell on the path should then be displayed in red.

A found path through the maze may look something like:

code in question:

equire 'gosu'

module ZOrder

BACKGROUND, MIDDLE, TOP $=*0.\mathrm{.}2$

end

MAP$\_$WIDTH $=200$

MAP$\_$HEIGHT $=200$

CELL$\_$DIM $=20$

class Cell

attr$\_$accessor :north, :south, :east, :west, :vacant, :visited, :on$\_$path

def initialize

@north $=$ nil

@south $=$ nil

@east $=$ nil

@west $=$ nil

@vacant $=$ false

@visited $=$ false

@on$\_$path $=$ false

end

end

class GameWindow $$ Gosu::Window

def initialize

super MAP$\_$WIDTH, MAP$\_$HEIGHT, false

self.caption $=$ "Map Creation"

@path $=$ nil

@start$\_$cells $=[]$

@end$\_$cells $=[]$

x$\_$cell$\_$count $=$ MAP$\_$WIDTH $/$ CELL$\_$DIM

y$\_$cell$\_$count $=$ MAP$\_$HEIGHT $/$ CELL$\_$DIM

@columns $=$ Array.new$($x$\_$cell$\_$count$)\{$ Array.new$($y$\_$cell$\_$count$)\{$ Cell.new $\}\}$

# Set the neighbours of each cell

@columns.each$\_$with$\_$index do $|$column$,$ column$\_$index$|$

column.each$\_$with$\_$index do $|$cell$,$ row$\_$index$|$

cell.north $=$ @columns$[$column$\_$index$][$row$\_$index $-1]$ if row$\_$index $>0$

cell.south $=$ @columns$[$column$\_$index$][$row$\_$index $+1]$ if row$\_$index $$ y$\_$cell$\_$count $-1$

cell.east $=$ @columns$[$column$\_$index $+1][$row$\_$index$]$ if column$\_$index $$ x$\_$cell$\_$count $-1$

cell.west $=$ @columns$[$column$\_$index $-1][$row$\_$index$]$ if column$\_$index $>0$

end

end

end

def needs$\_$cursor?

true

end

def mouse$\_$over$\_$cell$($mouse$\_$x$,$ mouse$\_$y$)$

cell$\_$x $=$ mouse$\_$x $/$ CELL$\_$DIM

cell$\_$y $=$ mouse$\_$y $/$ CELL$\_$DIM

$[$cell$\_$x$,$ cell$\_$y$]$

end

def button$\_$down$($id$)$

case id

when Gosu::MsLeft

cell$\_$x$,$ cell$\_$y $=$ mouse$\_$over$\_$cell$($mouse$\_$x$,$ mouse$\_$y$)$

cell $=$ @columns$[$cell$\_$x$][$cell$\_$y$]$

cell.vacant $=$ true

@start$\_$cells $$ cell if cell$\_$x $==0$ # Add cell to start cells if on left edge

when Gosu::MsRight

cell$\_$x$,$ cell$\_$y $=$ mouse$\_$over$\_$cell$($mouse$\_$x$,$ mouse$\_$y$)$

start$\_$cell $=$ @columns$[$cell$\_$x$][$cell$\_$y$]$

if $!$@start$\_$cells.empty? && start$\_$cell.vacant

search$($start$\_$cell, @columns.last$[$cell$\_$y$])$ # Find path to right edge

end

end

end

def search$($current$\_$cell, end$\_$cell$)$

return false if current$\_$cell.nil? $||$ current$\_$cell.visited $||$ current$\_$cell.vacant

current$\_$cell.visited $=$ true

if current$\_$cell $==$ end$\_$cell

current$\_$cell.on$\_$path $=$ true

return true

end

$[$current$\_$cell.north, current$\_$cell.south, current$\_$cell.east, current$\_$cell.west$].$each do $|$neighbor$|$

if search$($neighbor$,$ end$\_$cell$)$

current$\_$cell.on$\_$path $=$ true

return true

end

end

false

end

def draw

@columns.each$\_$with$\_$index do $|$column$,$ column$\_$index$|$

column.each$\_$with$\_$index do $|$cell$,$ row$\_$index$|$

color $=$ cell.vacant $?$ Gosu::Color::YELLOW : Gosu::Color::GREEN

color $=$ Gosu::Color::RED if cell.on$\_$path

Gosu.draw$\_$rect$($column$\_$index $*$ CELL$\_$DIM, row$\_$index $*$ CELL$\_$DIM, CELL$\_$DIM, CELL$\_$DIM, color, ZOrder::TOP, mode$=$:default$)$

end

end

end

end

window $=$ GameWindow.new

window.show Maze$\_$creation.rb

require 'gosu'

module zorder

BACKGROUND, MIDDLE, TOP $=**0.\mathrm{.}2$

end

MAP$\_$WIDTH $=200$

MAP$\_$HEIGHT $=200$

CELL$\_$DIM $=20$

class Cell

attr$\_$accessor :north, :south, :east, :west, :vacant, :visited, :on$\_$path

def initialize

@north $=$ nil

@south $=$ nil

@east $=$ nil

ewest $=$ nil

@vacant $=$ false

@visited $=$ false

@on$\_$path $=$ false

end

end

class GameWindow $$ Gosu::Window

def initialize

super MAP$\_$WIDTH, MAP$\_$HEIGHT, false

self.caption $=$ "Map Creation"

@path $=$ nil

@start$\_$cells $=[]$

@end$\_$cells $=[]$

x$\_$cell$\_$count $=$ MAP$\_$WIDTH $/$ CELL$\_$DIM

y$\_$cell$\_$count $=$ MAP$\_$HEIGHT $/$ CELL$\_$DIM