C++ (Cpp) Nodes::last示例

int UltimateTicTacToeMontecarloAI::expand(int leafIndex, Nodes& nodes, int const player) const
{
  Node& node = nodes[leafIndex];
  node.children.reserve(maxChildren);
  Moves options = movementOptions(node.board, node.previousMove);
  int turn = node.previousMove > 0 ? otherPlayer(node.board.grids.at(node.previousMove)) : player;

  int mostPromisingChildIndex = -1;
  int mostPromisingChildScore = 0;

  while(node.children.size() < maxChildren && !options.empty())
  {
    Move move = options.takeAt(qrand() % options.size());
    int childIndex = nodes.size();
    node.children.append(childIndex);
    Board newBoard(node.board);
    nodes.append( Node {0, 1, playMove(newBoard, move, turn), move, leafIndex, Node::Children()});
    int score = scoreBoard(nodes.last().board, player);
    if(score > mostPromisingChildScore || mostPromisingChildIndex < 0)
    {
      mostPromisingChildIndex = childIndex;
      mostPromisingChildScore = score;
    }
  }

  return mostPromisingChildIndex;
}