Regarding TXT to find and delete duplicate data. Please help me

yunshenxin

The text is as follows
aaaa
bbbb
ccc
ddd
aaaa
eee
fff
gggg

How to delete duplicates ~~ headache ~

xclzc17

procedure TForm1.Button1Click (Sender: TObject);
var
  s: TStringList;
  I: Integer;
begin
  s: = TStringList.Create;
....
  s.Sort;
  for i: = s.Count-1 downto 1 do
    if s [i] = s [i-1] then
      s.Delete (i);
    ...
end;

yunshenxin

I wrote this, but the problem is still not solved ~~ aaaa is still not deleted ~~

Lists: = TStringList.Create;
Lists.LoadFromFile (opendialog1.FileName);
progressbar1.Max: = lists.Count-1;
 for i: = lists.Count-1 downto 1 do
 begin
    if lists [i] = lists [i-1] then
    begin
      lists.Delete (i);
    lists.SaveToFile (opendialog1.FileName);
    end;
 end;

xclzc17

You are too careless to copy wrong

Lists: = TStringList.Create;
Lists.LoadFromFile (opendialog1.FileName);
Lists.Sort;
progressbar1.Max: = lists.Count-1;
 for i: = lists.Count-1 downto 1 do
 begin
    if lists [i] = lists [i-1] then
    begin
      lists.Delete (i);

    end;
 end;
lists.SaveToFile (opendialog1.FileName);

star0528

There is a problem with your algorithm. Always compare the Nth string with the N-1th string. If it is not adjacent, it will be impossible to compare.
You should compare each one with any one of them.
Such as using the first and second to last comparison
Use the second and third to the last comparison
Use the third and fourth to last comparison
...
Only then can we compare them all

winterman

if s[i] = s[i-1] then
      s.Delete(i);

something wrong

winterman

The easiest way:
Open UltraEdit-File-Sort-Advanced Sort/Options-Select [Delete Duplicates]

winterman

sorry didn't see s.sort
But even so, it is not recommended to delete s in the count loop of i from s

In fact, it can also be written like this
procedure TForm1.Button1Click(Sender: TObject);
var
  s,b: TStringList;
  I: Integer;
begin
  s := TStringList.Create;
  b := TStringList.Create;

....
  for i := s.Count-1 downto 1 do
    if b.IndexOf(s[i])<0 then
      b.Add(s[i]);
    ...
b.SaveToFile
b.free;
s.free;
end;

wenji000

Simple problems are complicated

s := TStringList.Create;
s.Duplicates := dupIgnore;
s.Sorted := True;
try
s.LoadFromFile(XXXX);
finally
Freeandnil(s);
end;