Added solution for "Day 6: Wait For It", part 2

solvers/UWaitForIt.pas

@@ -30,6 +30,8 @@ type
 
   TWaitForIt = class(TSolver)
     FTimes, FDistances: specialize TFPGList<Cardinal>;
+    FLongTime, FLongDistance: UInt64;
+    function CalcRange(const ATime, ADistance: UInt64): Cardinal;
   public
     constructor Create;
     destructor Destroy; override;
@@ -43,6 +45,18 @@ implementation
 
 { TWaitForIt }
 
+function TWaitForIt.CalcRange(const ATime, ADistance: UInt64): Cardinal;
+var
+  x1, x2: Integer;
+  p, s: Double;
+begin
+  p := ATime / 2;
+  s := Sqrt(p * p - ADistance);
+  x1 := Math.Floor(p - s + 1);
+  x2 := Math.Ceil(p + s - 1);
+  Result := x2 - x1 + 1;
+end;
+
 constructor TWaitForIt.Create;
 begin
   FTimes := specialize TFPGList<Cardinal>.Create;
@@ -60,37 +74,42 @@ procedure TWaitForIt.ProcessDataLine(const ALine: string);
 var
   split: TStringArray;
   list: specialize TFPGList<Cardinal>;
+  value: PUInt64;
   i: Integer;
+  cleaned: string;
 begin
   split := ALine.Split([' ', ':']);
   if split[0] = 'Time' then
-    list := FTimes
+  begin
+    list := FTimes;
+    value := @FLongTime;
+  end
   else if split[0] = 'Distance' then
-    list := FDistances
+  begin
+    list := FDistances;
+    value := @FLongDistance;
+  end
   else
     Exit;
 
+  cleaned := '';
   for i := 1 to Length(split) - 1 do
     if split[i] <> '' then
     begin
       list.Add(StrToDWord(split[i]));
+      cleaned := Concat(cleaned, split[i]);
     end;
+  value^ := StrToUInt64(cleaned);
 end;
 
 procedure TWaitForIt.Finish;
 var
-  i, x1, x2: Integer;
+  i: Integer;
-  p, s: Double;
 begin
   FPart1 := 1;
   for i := 0 to FTimes.Count - 1 do
-  begin
+    FPart1 := FPart1 * CalcRange(FTimes[i], FDistances[i]);
-    p := FTimes[i] / 2;
+  FPart2 := CalcRange(FLongTime, FLongDistance);
-    s := Sqrt(p * p - FDistances[i]);
-    x1 := Math.Floor(p - s + 1);
-    x2 := Math.Ceil(p + s - 1);
-    FPart1 := FPart1 * (x2 - x1 + 1);
-  end;
 end;
 
 function TWaitForIt.GetDataFileName: string;

tests/UWaitForItTestCases.pas

@@ -62,7 +62,7 @@ end;
 
 procedure TWaitForItFullDataTestCase.TestPart2;
 begin
-  AssertEquals(-1, FSolver.GetResultPart2);
+  AssertEquals(30077773, FSolver.GetResultPart2);
 end;
 
 { TWaitForItExampleTestCase }
@@ -79,7 +79,7 @@ end;
 
 procedure TWaitForItExampleTestCase.TestPart2;
 begin
-  AssertEquals(-1, FSolver.GetResultPart2);
+  AssertEquals(71503, FSolver.GetResultPart2);
 end;
 
 initialization