$$

$19$:$54$

exam$\_24\mathrm{.}11\mathrm{.}202318012024$

$--$Open the file

function readGrid$($filename$)$

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

if not file then

print$("$File not found"$)$

return nil

end

$--$Read the grid of numbers from a file

local grid $=\{\}$

local dimensions$=$ file:read$("*$line$")$

local rows, cols $=$ dimensions:match $((\%d+)\%s+(\%d+))$

rows, cols $=$ tonumber$($rows$),$ tonumber$($cols$)$

for $i=1,$ rows do

grid $[i]=\{\}$

for $j=1,$ cols do

$--$Iniciate the grid with a default value

grid$[i][j]=-1$

end

end

for line in file:lines$()$ do

local row, col, val $=$ line:match $($:$(\%d+{)}^{\text{'}\text{'}}\}$

row,col,val $=$ tonumber$($row$),$ tonumber$($col$),$

tonumber$($val$)$

if row and col and val then

if grid$[$row$]$ and grid$[$col$]$ then

grid $[row][col]=$ val $--$ Value in grid update

end

end

end

$--$Close the file

file:close $()$

return grid

end

$--$Function to show values in a specific column of grid function showColumn$($grid$,$ col$)$

if col$<mn\; id="EditorElement\_1394511">1</mn>$ or col $>$ #grid $[1]$ then

nrint $("$Invalid column numher"$)$