Data commit

Task/Inverted-index/Delphi/inverted-index.delphi

@@ -0,0 +1,190 @@
+program Inverted_index;
+
+{$APPTYPE CONSOLE}
+
+uses
+  System.SysUtils,
+  system.Generics.Collections,
+  SYstem.IOUtils;
+
+type
+  TIndex = class
+  private
+    FFileNames: TArray<string>;
+    FIndexs: TDictionary<string, string>;
+    class function SplitWords(Text: string): TArray<string>; static;
+    function StoreFileName(FileName: TFileName): string;
+    procedure StoreLine(Line, Id: string);
+    procedure StoreWord(aWord, Id: string);
+    function DecodeFileName(Indexed: string): string;
+  public
+    procedure AddFile(FileName: TFileName);
+    constructor Create;
+    destructor Destroy; override;
+    function Search(aWord: string): string;
+    property Index[aWord: string]: string read Search; default;
+  end;
+
+{ TIndex }
+
+constructor TIndex.Create;
+begin
+  FIndexs := TDictionary<string, string>.Create();
+  SetLength(FFileNames, 0);
+end;
+
+function TIndex.DecodeFileName(Indexed: string): string;
+var
+  f: string;
+  i: integer;
+begin
+  Result := Indexed;
+  if Length(FFileNames) > 0 then
+    for i := 0 to High(FFileNames) do
+    begin
+      f := FFileNames[i];
+      Result := Result.Replace(format('(%x)', [i]), f);
+    end;
+end;
+
+destructor TIndex.Destroy;
+begin
+  FIndexs.Free;
+  inherited;
+end;
+
+function TIndex.Search(aWord: string): string;
+begin
+  aWord := AnsiLowerCase(aWord);
+  if FIndexs.ContainsKey(aWord) then
+    Result := 'found in ' + DecodeFileName(FIndexs[aWord])
+  else
+    Result := 'not found';
+end;
+
+class function TIndex.SplitWords(Text: string): TArray<string>;
+const
+  WORD_CHARSET: set of char = (['a'..'z', 'A'..'Z', 'á', 'é', 'í', 'ó', 'ú', 'ã',
+    'õ', 'à', 'è', 'ì', 'ò', 'ù', 'Á', 'É', 'Í', 'Ó', 'Ú', 'Ã', 'Õ', 'À', 'È',
+    'Ì', 'Ò', 'Ù', 'ä', 'ë', 'ï', 'ö', 'ü', 'ç', 'Ç', '_', '0'..'9']);
+
+  procedure Append(var value: string);
+  begin
+    if not value.IsEmpty then
+    begin
+      SetLength(result, length(result) + 1);
+      result[high(result)] := value;
+      value := '';
+    end;
+  end;
+
+var
+  c: Char;
+  inWord, isWordChar: boolean;
+  w: string;
+begin
+  inWord := False;
+  w := '';
+  SetLength(result, 0);
+  for c in Text do
+  begin
+    isWordChar := (c in WORD_CHARSET);
+    if inWord then
+      if isWordChar then
+        w := w + c
+      else
+      begin
+        Append(w);
+        inWord := false;
+        Continue;
+      end;
+
+    if not inWord and isWordChar then
+    begin
+      inWord := True;
+      w := c;
+    end;
+  end;
+  if inWord then
+    Append(w);
+end;
+
+function TIndex.StoreFileName(FileName: TFileName): string;
+begin
+  SetLength(FFileNames, length(FFileNames) + 1);
+  FFileNames[High(FFileNames)] := FileName;
+  Result := format('"(%x)"', [High(FFileNames)]);
+end;
+
+procedure TIndex.StoreLine(Line, Id: string);
+var
+  Words: TArray<string>;
+  w: string;
+begin
+  Words := SplitWords(Line);
+  for w in Words do
+    StoreWord(w, Id);
+end;
+
+procedure TIndex.StoreWord(aWord, Id: string);
+begin
+  aWord := AnsiLowercase(aWord);
+  if FIndexs.ContainsKey(aWord) then
+  begin
+    if (FIndexs[aWord].IndexOf(Id) = -1) then
+      FIndexs[aWord] := FIndexs[aWord] + ', ' + Id;
+  end
+  else
+    FIndexs.Add(aWord, Id);
+end;
+
+procedure TIndex.AddFile(FileName: TFileName);
+var
+  Lines: TArray<string>;
+  Line: string;
+  Id: string;
+begin
+  if not FileExists(FileName) then
+    exit;
+  Lines := TFile.ReadAllLines(FileName);
+
+  if length(Lines) = 0 then
+    exit;
+
+  // Remove this line if you want full filename
+  FileName := ExtractFileName(FileName);
+
+  Id := StoreFileName(FileName);
+
+  for Line in Lines do
+    StoreLine(Line, Id);
+end;
+
+var
+  Index: TIndex;
+  FileNames: TArray<TFileName> = ['file1.txt', 'file2.txt', 'file3.txt'];
+  FileName: TFileName;
+  Querys: TArray<string> = ['Cat', 'is', 'banana', 'it', 'what'];
+  Query, Found: string;
+
+begin
+  Index := TIndex.Create;
+
+  for FileName in FileNames do
+    Index.AddFile(FileName);
+
+  for Query in Querys do
+    Writeln(format('"%s" %s'#10, [Query, Index[Query]]));
+
+  repeat
+    Writeln('Enter a word to search for: (q to quit)');
+    Readln(Query);
+
+    if Query = 'q' then
+      Break;
+
+    Writeln(format('"%s" %s'#10, [Query, Index[Query]]));
+  until False;
+
+  Index.Free;
+end.