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

endOpens a text file called grid. txt which contains a series of numbers line by line in a

rectangular pattern and reads it into an appropriate data structure of your choice. The rows

and columns represent cities $($numbered from $0)$ while the values at the intersections

represent the distances between those cities. Zero represents the case where there is no link

between the cities.

For numbering purposes the rows and values are indexed on a $0-$index basis $($i$.$e$.$ the

first row is row $0$ and the first column is column $0)$

Once the file is loaded your program must respond to commands given to it from the

standard input stream. Each command will be represented by a unique word followed by a

set of numerical parameters. Each command and parameter will be separated by a newline

character.

For example:

areneighbours

$0$

$4$

will output Yes