Added solution for "Day 1: Trebuchet?!", part 2

puzzles/utrebuchet.pas

@@ -22,48 +22,31 @@ unit UTrebuchet;
 interface
 
 uses
-  Classes, SysUtils;
+  Classes, SysUtils, TypInfo;
 
 type
+  TSpelledOutDigit = (zero, one, two, three, four, five, six, seven, eight, nine);
 
   { TTrebuchet }
 
   TTrebuchet = class(TObject)
   private
     FValue: Integer;
-    procedure RunSolution;
+    FConsiderSpelledOutDigits: Boolean;
     procedure ProcessDataLine(const ALine: string);
     function FindFirstDigit(const ALine: string; out OEndIndex: Integer): Integer;
     function FindLastDigit(const ALine: string; const AFirstDigit, AFirstDigitEndIndex: Integer): Integer;
     function CheckDigit(const ALine: string; const AIndex: Integer; out ODigit, OEndIndex: Integer): Boolean;
+    function CheckSpelledOutDigit(const ALine: string; const AIndex: Integer; out ODigit, OEndIndex: Integer): Boolean;
   public
-    constructor Create;
+    function Solve(const AConsiderSpelledOutDigits: Boolean): Integer;
-    class procedure Solve; static;
+    class procedure Run; static;
   end;
 
 implementation
 
 { TTrebuchet }
 
-procedure TTrebuchet.RunSolution;
-var
-  data: TextFile;
-  s: string;
-begin
-  AssignFile(data, ConcatPaths(['data', 'trebuchet_calibration_document.txt']));
-  try
-    reset(data);
-    while (not EOF(data)) do
-    begin
-      readln(data, s);
-      ProcessDataLine(s);
-    end;
-  finally
-    CloseFile(data)
-  end;
-  WriteLn('Part 1: ', FValue);
-end;
-
 procedure TTrebuchet.ProcessDataLine(const ALine: string);
 var
   first, endIndex, last: Integer;
@@ -100,27 +83,74 @@ begin
   begin
     ODigit := StrToInt(ALine[AIndex]);
     OEndIndex := AIndex;
+    Result := True;
+  end
+  else if FConsiderSpelledOutDigits and CheckSpelledOutDigit(ALine, AIndex, ODigit, OEndIndex) then
+  begin
     Result := true;
   end
   else begin
     ODigit := -1;
     OEndIndex := -1;
-    Result := false;
+    Result := False;
   end;
 end;
 
-constructor TTrebuchet.Create;
+function TTrebuchet.CheckSpelledOutDigit(const ALine: string; const AIndex: Integer; out ODigit, OEndIndex: Integer):
+  Boolean;
+var
+  i: Integer;
+  digitName: string;
 begin
-  FValue := 0;
+  for i := Ord(Low(TSpelledOutDigit)) to Ord(High(TSpelledOutDigit)) do
+  begin
+    digitName := GetEnumName(TypeInfo(TSpelledOutDigit), Ord(i));
+    if CompareStr(digitName, Copy(ALine, AIndex, digitName.Length)) = 0 then
+    begin
+      ODigit := i;
+      OEndIndex := AIndex + digitName.Length - 1;
+      Result := True;
+      Exit;
+    end;
+  end;
+
+  ODigit := -1;
+  OEndIndex := -1;
+  Result := False;
 end;
 
-class procedure TTrebuchet.Solve;
+function TTrebuchet.Solve(const AConsiderSpelledOutDigits: Boolean): Integer;
+var
+  data: TextFile;
+  s: string;
+begin
+  FValue := 0;
+  FConsiderSpelledOutDigits := AConsiderSpelledOutDigits;
+
+  AssignFile(data, ConcatPaths(['data', 'trebuchet_calibration_document.txt']));
+  try
+    reset(data);
+    while (not EOF(data)) do
+    begin
+      readln(data, s);
+      ProcessDataLine(s);
+    end;
+  finally
+    CloseFile(data)
+  end;
+
+  Result := FValue;
+end;
+
+class procedure TTrebuchet.Run;
 var
   trebuchet: TTrebuchet;
 begin
+  WriteLn;
   WriteLn('--- Day 1: Trebuchet?! ---');
   trebuchet := TTrebuchet.Create;
-  trebuchet.RunSolution;
+  WriteLn('Part 1: ', trebuchet.Solve(False));
+  WriteLn('Part 2: ', trebuchet.Solve(True));
   trebuchet.Free;
 end;