" successors = extend(current, closed)\n",
" for s in successors:\n",
" heapq.heappush(agenda, (len(current) + distance(s[-1], goal) - 1, s))\n",
" successors = extend(current, closed)\n",
" for s in successors:\n",
" heapq.heappush(agenda, (len(current) + distance(s[-1], goal) - 1, s))\n",