Data commit

Task/Yellowstone-sequence/Delphi/yellowstone-sequence.delphi

@@ -0,0 +1,81 @@
+program Yellowstone_sequence;
+
+{$APPTYPE CONSOLE}
+
+uses
+  System.SysUtils,
+  Boost.Generics.Collection,
+  Boost.Process;
+
+function gdc(x, y: Integer): Integer;
+begin
+  while y <> 0 do
+  begin
+    var tmp := x;
+    x := y;
+    y := tmp mod y;
+  end;
+  Result := x;
+end;
+
+function Yellowstone(n: Integer): TArray<Integer>;
+var
+  m: TDictionary<Integer, Boolean>;
+  a: TArray<Integer>;
+begin
+  m.Init;
+  SetLength(a, n + 1);
+  for var i := 1 to 3 do
+  begin
+    a[i] := i;
+    m[i] := True;
+  end;
+
+  var min := 4;
+
+  for var c := 4 to n do
+  begin
+    var i := min;
+    repeat
+      if not m[i, false] and (gdc(a[c - 1], i) = 1) and (gdc(a[c - 2], i) > 1) then
+      begin
+        a[c] := i;
+        m[i] := true;
+        if i = min then
+          inc(min);
+        Break;
+      end;
+      inc(i);
+    until false;
+  end;
+
+  Result := copy(a, 1, length(a));
+end;
+
+begin
+  var x: TArray<Integer>;
+  SetLength(x, 100);
+  for var i in Range(100) do
+    x[i] := i + 1;
+
+  var y := yellowstone(High(x));
+
+  writeln('The first 30 Yellowstone numbers are:');
+  for var i := 0 to 29 do
+    Write(y[i], ' ');
+  Writeln;
+
+  //Plotting
+
+  var plot := TPipe.Create('gnuplot -p', True);
+  plot.WritelnA('unset key; plot ''-''');
+
+  for var i := 0 to High(x) do
+    plot.WriteA('%d %d'#10, [x[i], y[i]]);
+  plot.WritelnA('e');
+
+  writeln('Press enter to close');
+  Readln;
+  plot.Kill;
+  plot.Free;
+end.