mixster

function DBSCAN(p: TPointArray; d, minPts: Integer): T2DPointArray;
var
  v, nC: array of Boolean;
  n, n2: TIntegerArray;
  i, dL, r, ii, nL, rL, iii, nL2: Integer;
begin
  dL := Length(p);
  SetLength(v, dL);
  SetLength(nC, dL);
  SetLength(Result, dL);
  r := 0;
  dL := dL - 1;
  for i := 0 to dL do
  begin
    v[i] := False;
    nC[i] := True;
  end;
  for i := 0 to dL do
  begin
    if (not (v[i])) then
    begin
      v[i] := True;
      SetLength(n, dL);
      nL := 0;
      for ii := 0 to dL do
      begin
        if (ii <> i) then
          if(not (v[ii])) then
            if (Distance(p[i].x, p[i].y, p[ii].x, p[ii].y) <= d) then
            begin
              n[nL] := ii;
              nL := nL + 1;
            end;
      end;
      SetLength(n, nL);
      if (nL >= minPts) then
      begin
        SetLength(Result[r], dL + 1);
        Result[r][0] := p[i];
        rL := 1;
        for ii := 0 to nL - 1 do
        begin
          if (not (v[n[ii]])) then
          begin
            v[n[ii]] := True;
            nL2 := 0;
            SetLength(n2, dL);
            for iii := 0 to dL do
              if (n[ii] <> iii) then
                if(not (v[iii])) then
                  if (nC[n[ii]]) then
                    if (Distance(p[n[ii]].x, p[n[ii]].y, p[iii].x, p[iii].y) <= d) then
                    begin
                      n2[nL2] := iii;
                      nL2 := nL2 + 1;
                    end;
            SetLength(n2, nL2);
            if (nL2 >= minPts) then
            begin
              SetLength(n, nL + nL2);
              for iii := nL to nL + nL2 - 1 do
                n[iii] := n2[iii - nL];
              nL := nL + nL2;
            end;
          end;
          if (nC[n[ii]]) then
          begin
            nC[n[ii]] := False;
            Result[r][rL] := p[n[ii]];
            rL := rL + 1;
          end;
        end;
        SetLength(Result[r], rL);
        r := r + 1;
      end;
    end;
  end;
  SetLength(Result, r);
end;