Оптимизация перебора

function g(v: integer): integer;
var
  i: integer;

begin
  result := 1;
  if (vis2 and (1 shl (v - 1)) = 0) then
    vis2 := vis2 + (1 shl (v - 1));

  for i := 1 to n do
    if (vis2 and (1 shl (i - 1)) = 0) and (matrix[v][i] = 1) then
      result := result + g(i);
end;

function dfs(v, deep: integer): integer;
var
  i, cnt, top: integer;

begin
  vis := vis + (1 shl (v - 1));

  result := get_ans_by_key(vis, v);
  if result <> -1 then
    exit;

  result := deep;
  global_ans := max(global_ans, result);

  for i := 1 to n do
    vis2[i] := vis[i];
  cnt := g(v);

  if deep + cnt - 1 > global_ans then begin

    top := 0;
    for i := 1 to n do
      if (matrix[v][i] = 1) and (vis and (1 shl (i - 1)) = 0) then begin
        inc(top);
        res[top] := dfs2(i);
        id[top] := i;
      end;

    if top <> 0 then begin
      qsort(1, top);

      for i := 1 to min(k, top) do
        if (matrix[v][id[i]] = 1) and (vis and (1 shl (id[i] - 1)) = 0) then
          result := max(result, dfs(id[i], deep + 1));
    end;
  end;

  put_key(vis, v, result);
  vis := vis - (1 shl (v - 1));
end;