local filename $=$ "grid.txt$"$

local grid $=$ loadGrid$($filename$)$

$--$function to load the grid from a file

function loadgrid$($filename$)$

local file $=$ io$.$ open $($filename $,"r")$

local grid $=\{\}$

if file then

for line in file:lines do

local row $=\{\}$

for num in line:gmatch $("\%$d$+")$ do

table.insert $($row$,$ tonumber$($num$))$

end

table.insert $($grid$,$ row$)$

end

file:close$()$

else

print$("$Error : Unable to open the file."$)$

os$.$exit$(1)$

end

return grid

end