用于C ++中抽象成员和类函数指针的Deep Copy构造函数

Question

This is a homework question. There is a pure virtual constructor involved, assume the original is not null

BST::BST(const BST& original) {

root = original.root;
if (root != nullptr)
{
    root = new Node();
    root->setValue( original.root->getValue() );
    Node* subtree = root;
    Node* temp = original.root;
    while (temp != nullptr)
    {
        subtree = new Node();
        subtree->setLeft(temp->getLeft());
        temp = temp->getLeft();
        subtree = subtree->getLeft();
    }
    temp = original.root;
    while (temp != nullptr)
    {
        subtree = new Node();
        subtree->setRight(temp->getRight());
        temp = temp->getRight();
        subtree = subtree->getLeft();
    }

}
}

//clone

  BST::VIRTUALBinary* clone() {
  return (new BST(*this)); }

//call to main

VIRTUALBinary* orig = new BST();
VIRTUALBinary* copy = new BST();
copy = orig;

//deleting original, hoping to keep copy in main

delete orig;

The copy seems to share the same value as the original function, because it deletes itself everytime I delete the original. Any help would be appreciated, much thanks.

Answer 1

You are only copying the pointers.

Use your clone method:

VIRTUALBinary* copy = orig->clone()