Word wheel: Difference between revisions

=={{header|Pascal}}==

{{works with|Free Pascal}}

<lang Pascal>

program WordWheel;

{$mode objfpc}{$H+}

uses

Classes, SysUtils;

const

WheelSize = 9;

MinLength = 3;

WordFile = 'unixdict.txt';

procedure search(pattern : string);

var

Allowed, Required, Available, w : string;

Len, i, p : integer;

WordList : TextFile;

Match : boolean;

begin

AssignFile(WordList, WordFile);

{$I-}

Reset(WordList);

{$I+}

if IOResult <> 0 then

begin

writeln('Could not open dictionary file ' + WordFile);

exit;

end;

Allowed := LowerCase(pattern);

Required := copy(Allowed, 5, 1);

while not eof(WordList) do

begin

readln(WordList, w);

Len := length(w);

Available := Allowed;

if (Len < MinLength) or (Len > WheelSize) then continue;

if pos(Required, w) = 0 then continue;

Match := True;

for i := 1 to Len do

begin

p := pos(w[i], Available);

if p > 0 then

{ prevent re-use of letter }

delete(Available, p, 1)

else

begin

Match := False;

break;

end;

end;

if Match then

writeln(w);

end;

end;

{ exercise the procedure }

begin

search('NDEOKGELW');

end.

</lang>

{{out}}

<pre>

eke

elk

keel

keen

keg

ken

keno

knee

kneel

knew

know

knowledge

kong

leek

week

wok

woke

</pre>