Added solution for "Day 7: Camel Cards", part 2

solvers/UCamelCards.pas

@@ -39,12 +39,13 @@ type
   TCardHand = class
   private
     FHand: string;
-    FType: TCardHandType;
+    FType, FJokerType: TCardHandType;
     FBid: Cardinal;
-    function GetCardValue(const ACard: Char): Cardinal;
+    procedure CalcCountersFromHand(constref counters: TCardCounters);
+    function CalcTypeFromCounters(constref counters: TCardCounters): TCardHandType;
+    function CalcJokerTypeFromCounters(constref counters: TCardCounters): TCardHandType;
   public
     constructor Create(const ALine: string);
-    function CompareTo(constref AOther: TCardHand): Integer;
     property Bid: Cardinal read FBid;
   end;
 
@@ -53,8 +54,20 @@ type
   { TCardHandComparer }
 
   TCardHandComparer = class(TInterfacedObject, specialize IComparer<TCardHand>)
+  protected
+    function CompareCardValue(constref AHand1, AHand2: TCardHand): Integer;
+    function GetCardValue(const ACard: Char): Cardinal; virtual;
   public
-    function Compare(constref AHand1, AHand2: TCardHand): Integer;
+    function Compare(constref AHand1, AHand2: TCardHand): Integer; virtual;
+  end;
+
+  { TJokerCardHandComparer }
+
+  TJokerCardHandComparer = class(TCardHandComparer)
+  protected
+    function GetCardValue(const ACard: Char): Cardinal; override;
+  public
+    function Compare(constref AHand1, AHand2: TCardHand): Integer; override;
   end;
 
   { TCamelCards }
@@ -75,33 +88,14 @@ implementation
 
 { TCardHand }
 
-function TCardHand.GetCardValue(const ACard: Char): Cardinal;
-begin
-  if not TryStrToDWord(ACard, Result) then
-    case ACard of
-      'A': Result := 14;
-      'K': Result := 13;
-      'Q': Result := 12;
-      'J': Result := 11;
-      'T': Result := 10;
-      else Result := 0;
-    end;
-end;
-
-constructor TCardHand.Create(const ALine: string);
+procedure TCardHand.CalcCountersFromHand(constref counters: TCardCounters);
 var
-  split: TStringArray;
-  counters: TCardCounters;
   counter: TCardCounter;
   i: Integer;
   c: Char;
   found: Boolean;
 begin
-  split := ALine.Split(' ');
-  FHand := split[0];
-  FBid := StrToDWord(split[1]);
-
-  counters := TCardCounters.Create;
+  counters.Clear;
 
   // Creates a counter for each different card value and counts cards per card value.
   for c in FHand do
@@ -127,45 +121,131 @@ begin
       counters.Add(counter);
     end;
   end;
-
-  // Determines the hand type from the counters.
-  case counters.Count of
-    1: FType := htFiveOfAKind;
-    2:
-      if (counters[0].Count = 4) or (counters[1].Count = 4) then
-        FType := htFourOfAKind
-      else
-        FType := htFullHouse;
-    3:
-      if (counters[0].Count = 3) or (counters[1].Count = 3) or (counters[2].Count = 3) then
-        FType := htThreeOfAKind
-      else
-        FType := htTwoPair;
-    4: FType := htOnePair;
-    5: FType := htHighCard;
-  end;
-
-  counters.Free;
 end;
 
-function TCardHand.CompareTo(constref AOther: TCardHand): Integer;
-var
-  i: Integer;
+function TCardHand.CalcTypeFromCounters(constref counters: TCardCounters): TCardHandType;
 begin
-  Result := Ord(FType) - Ord(AOther.FType);
-  i := 1;
-  while (Result = 0) and (i <= FHand.Length) do
-  begin
-    Result := GetCardValue(FHand[i]) - GetCardValue(AOther.FHand[i]);
-    Inc(i);
+  // Determines the hand type from the counters.
+  case counters.Count of
+    1: Result := htFiveOfAKind;
+    2:
+      if (counters[0].Count = 4) or (counters[1].Count = 4) then
+        Result := htFourOfAKind
+      else
+        Result := htFullHouse;
+    3:
+      if (counters[0].Count = 3) or (counters[1].Count = 3) or (counters[2].Count = 3) then
+        Result := htThreeOfAKind
+      else
+        Result := htTwoPair;
+    4: Result := htOnePair;
+    5: Result := htHighCard;
   end;
 end;
 
+function TCardHand.CalcJokerTypeFromCounters(constref counters: TCardCounters): TCardHandType;
+var
+  i, maxCount, maxCountIndex, jokerIndex: Integer;
+  jokerCounter, counter: TCardCounter;
+begin
+  if counters.Count > 1 then
+  begin
+    // Finds Jokers and the best card value.
+    maxCount := 0;
+    jokerIndex := -1;
+    for i := 0 to counters.Count - 1 do
+    begin
+      if counters[i].Card = 'J' then
+      begin
+        jokerIndex := i;
+        jokerCounter := counters[i];
+      end
+      else if maxCount < counters[i].Count then
+      begin
+        maxCount := counters[i].Count;
+        maxCountIndex := i;
+      end;
+    end;
+
+    // Uses Jokers for the best card value.
+    if jokerIndex >= 0 then
+    begin
+      counter := counters[maxCountIndex];
+      Inc(counter.Count, jokerCounter.Count);
+      counters[maxCountIndex] := counter;
+      counters.Delete(jokerIndex);
+    end;
+  end;
+
+  Result := CalcTypeFromCounters(counters);
+end;
+
+constructor TCardHand.Create(const ALine: string);
+var
+  split: TStringArray;
+  counters: TCardCounters;
+begin
+  split := ALine.Split(' ');
+  FHand := split[0];
+  FBid := StrToDWord(split[1]);
+
+  counters := TCardCounters.Create;
+  CalcCountersFromHand(counters);
+  FType := CalcTypeFromCounters(counters);
+  FJokerType := CalcJokerTypeFromCounters(counters);
+  counters.Free;
+end;
+
 { TCardHandComparer }
 
+function TCardHandComparer.CompareCardValue(constref AHand1, AHand2: TCardHand): Integer;
+var
+  i: Integer;
+begin
+  Result := 0;
+  i := 1;
+  while (Result = 0) and (i <= AHand1.FHand.Length) do
+  begin
+    Result := GetCardValue(AHand1.FHand[i]) - GetCardValue(AHand2.FHand[i]);
+    Inc(i);
+  end;
+end;
+
+function TCardHandComparer.GetCardValue(const ACard: Char): Cardinal;
+begin
+  if not TryStrToDWord(ACard, Result) then
+    case ACard of
+      'A': Result := 14;
+      'K': Result := 13;
+      'Q': Result := 12;
+      'J': Result := 11;
+      'T': Result := 10;
+      else Result := 0;
+    end;
+end;
+
 function TCardHandComparer.Compare(constref AHand1, AHand2: TCardHand): Integer;
 begin
-  Result := AHand1.CompareTo(AHand2);
+  Result := Ord(AHand1.FType) - Ord(AHand2.FType);
+  if Result = 0 then
+    Result := CompareCardValue(AHand1, AHand2);
+end;
+
+{ TJokerCardHandComparer }
+
+function TJokerCardHandComparer.GetCardValue(const ACard: Char): Cardinal;
+begin
+  if ACard = 'J' then
+    Result := 1
+  else
+    Result := inherited GetCardValue(ACard);
+end;
+
+function TJokerCardHandComparer.Compare(constref AHand1, AHand2: TCardHand): Integer;
+begin
+  Result := Ord(AHand1.FJokerType) - Ord(AHand2.FJokerType);
+  if Result = 0 then
+    Result := CompareCardValue(AHand1, AHand2);
 end;
 
 { TCamelCards }
@@ -189,6 +269,7 @@ end;
 procedure TCamelCards.Finish;
 var
   comparer: TCardHandComparer;
+  jokerComparer: TJokerCardHandComparer;
   i: Integer;
 begin
   comparer := TCardHandComparer.Create;
@@ -197,6 +278,13 @@ begin
 
   for i := 0 to FHands.Count - 1 do
     Inc(FPart1, FHands[i].Bid * (i + 1));
+
+  jokerComparer := TJokerCardHandComparer.Create;
+  FHands.Sort(jokerComparer);
+  jokerComparer.Free;
+
+  for i := 0 to FHands.Count - 1 do
+    Inc(FPart2, FHands[i].Bid * (i + 1));
 end;
 
 function TCamelCards.GetDataFileName: string;

tests/UCamelCardsTestCases.pas

@@ -62,7 +62,7 @@ end;
 
 procedure TCamelCardsFullDataTestCase.TestPart2;
 begin
-  AssertEquals(-1, FSolver.GetResultPart2);
+  AssertEquals(254115617, FSolver.GetResultPart2);
 end;
 
 { TCamelCardsExampleTestCase }
@@ -79,7 +79,7 @@ end;
 
 procedure TCamelCardsExampleTestCase.TestPart2;
 begin
-  AssertEquals(-1, FSolver.GetResultPart2);
+  AssertEquals(5905, FSolver.GetResultPart2);
 end;
 
 initialization