A-M baby

Task/Factorial/Delphi/factorial-1.delphi

@@ -0,0 +1,16 @@
+program Factorial1;
+
+{$APPTYPE CONSOLE}
+
+function FactorialIterative(aNumber: Integer): Int64;
+var
+  i: Integer;
+begin
+  Result := 1;
+  for i := 1 to aNumber do
+    Result := i * Result;
+end;
+
+begin
+  Writeln('5! = ', FactorialIterative(5));
+end.

Task/Factorial/Delphi/factorial-2.delphi

@@ -0,0 +1,15 @@
+program Factorial2;
+
+{$APPTYPE CONSOLE}
+
+function FactorialRecursive(aNumber: Integer): Int64;
+begin
+  if aNumber < 1 then
+    Result := 1
+  else
+    Result := aNumber * FactorialRecursive(aNumber - 1);
+end;
+
+begin
+  Writeln('5! = ', FactorialRecursive(5));
+end.

Task/Factorial/Delphi/factorial-3.delphi

@@ -0,0 +1,24 @@
+program Factorial3;
+
+{$APPTYPE CONSOLE}
+
+function FactorialTailRecursive(aNumber: Integer): Int64;
+
+  function FactorialHelper(aNumber: Integer; aAccumulator: Int64): Int64;
+  begin
+    if aNumber = 0 then
+      Result := aAccumulator
+    else
+      Result := FactorialHelper(aNumber - 1, aNumber * aAccumulator);
+    end;
+
+begin
+  if aNumber < 1 then
+    Result := 1
+  else
+    Result := FactorialHelper(aNumber, 1);
+end;
+
+begin
+  Writeln('5! = ', FactorialTailRecursive(5));
+end.