c++ - 为什么我在这里泄漏内存(深度优先搜索)C++？

Question

int Solver::negamax(Position* pos,int alpha,int beta, int color, int depth ) {
  if(depth==0 || is_final(pos)){
    return evaluate(pos);
  }
  else{
    vector < Position* > moves = generate_moves(pos->get_board());
    vector < Position* >::iterator move;
    int min = 99999;
    for(move = moves.begin(); move < moves.end(); move++){
      int val = negamax(*move,alpha, beta, -color, depth - 1 );
      if(val <= min){
        min = val;
        delete best;
        best = NULL;
        best = (*move)->get_board();

      }
      else{
        delete *move; //So this isnt cleaning up?
        *move = NULL;
      }
     }
     min = -min;
     return min;
     }

 }

vector < Position* > TakeAwaySolver::generate_moves(Board *brd){
  TakeAwayBoard *board = static_cast<TakeAwayBoard*>(brd);
  vector < Position* > moves;
  if(board->get_data() >= 3){
     TakeAwayBoard *b = new TakeAwayBoard(board->get_data() - 3);
     Position* p = new Position(b);
     moves.push_back(p);
  }
  if(board->get_data() >= 2){
     TakeAwayBoard *b = new TakeAwayBoard(board->get_data() - 2);
     Position* p = new Position(b);
     moves.push_back(p);
  }
  TakeAwayBoard *b = new TakeAwayBoard(board->get_data() - 1);
  Position* p = new Position(b);
  moves.push_back(p);
  return moves;

我对我的程序进行了 valgrinded，显然我正在泄漏内存。似乎我正在删除所有未使用的对象，但也许我不理解某些东西。 generate_moves() 确实为每个被插入的对象分配内存。评估返回 1。我是否有可能在任何位置泄漏内存？

Answer 1

您有一个 if/else，其中 *move 仅在其中一个路径中被删除。我会在那里检查。

for(move = moves.begin(); move < moves.end(); move++){
          int val = negamax(*move,alpha, beta, -color, depth - 1 );
          if(val <= min){
            min = val;
            delete best;
            best = NULL;
            best = (*move)->get_board();
                                           //best is deleted, but *move is not
          }
          else{
            delete *move;
            *move = NULL;
          }
         }