unit uHighScores; interface uses System.Generics.Collections; type IScores = interface(IInvokable) ['{3D174C80-BA8D-4D92-AB1B-DA29ED0812CE}'] function Scores: TList; function Latest: integer; function Highest: integer; function personalTopThree: TList; function Report: string; end; function NewScores(aInputScores: TArray): IScores; implementation uses System.SysUtils; type TScores = class(TInterfacedObject, IScores) private FScores: TList; public constructor Create(const aInputScores: TArray); destructor Destroy; override; function Scores: TList; function Latest: integer; function Highest: integer; function personalTopThree: TList; function Report: string; end; { TScores } function NewScores(aInputScores: TArray): IScores; begin result := TScores.Create(aInputScores); end; constructor TScores.Create(const aInputScores: TArray); begin FScores := TList.Create; FScores.AddRange(aInputScores); end; destructor TScores.Destroy; begin FScores.DisposeOf; inherited; end; function TScores.Highest: integer; begin var lScoresList := TList.Create; lScoresList.AddRange(FScores); lScoresList.Sort; Result := lScoresList.Last; lScoresList.DisposeOf; end; function TScores.Latest: integer; begin Result := FScores.Last; end; function TScores.Report: string; begin var L := Latest; var H := Highest; if L = H then Result := format('Your latest score was %d. That''s your personal best!',[L]) else Result := format('Your latest score was %d. That''s %d short of your personal best!',[L, H - L]); end; function TScores.Scores: TList; begin Result := FScores; end; function TScores.personalTopThree: TList; begin var lTopThree := TList.Create; lTopThree.AddRange(FScores); lTopThree.Sort; lTopThree.Reverse; if lTopThree.Count > 3 then lTopThree.Count := 3; Result := lTopThree; end; end.