Data commit

Task/Self-describing-numbers/Delphi/self-describing-numbers.delphi

@@ -0,0 +1,50 @@
+{This routine would normally be in a library. It is shown here for clarity.}
+
+
+procedure GetDigitsRev(N: integer; var IA: TIntegerDynArray);
+{Get an array of the integers in a number}
+{Numbers returned from most to least significant}
+var T,I,DC: integer;
+begin
+DC:=Trunc(Log10(N))+1;
+SetLength(IA,DC);
+for I:=DC-1 downto 0 do
+	begin
+	T:=N mod 10;
+	N:=N div 10;
+	IA[I]:=T;
+	end;
+end;
+
+
+
+function IsSelfDescribing(N: integer): boolean;
+var IA: TIntegerDynArray;
+var CA: array [0..9] of integer;
+var I: integer;
+begin
+{Get digits, High-low order}
+GetDigitsRev(N,IA);
+for I:=0 to High(CA) do CA[I]:=0;
+{Count number of each digit 0..9}
+for I:=0 to High(IA) do
+	begin
+	CA[IA[I]]:=CA[IA[I]]+1;
+	end;
+Result:=False;
+{Compare original number with counts}
+for I:=0 to High(IA) do
+ if IA[I]<>CA[I] then exit;
+Result:=True;
+end;
+
+
+procedure SelfDescribingNumbers(Memo: TMemo);
+var I: integer;
+begin
+for I:=0 to 100000000-1 do
+ if IsSelfDescribing(I) then
+	begin
+	Memo.Lines.Add(IntToStr(I));
+	end;
+end;