7041.md

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Solution to 7041: Cloning tree nodes

See code at solutions/code/tutorialquestions/question7041

A tree node can be cloned using a recursive method as follows:

public TreeNode<E> clone() {
  TreeNode<E> result = new TreeNode<E>(getNumberOfChildren());
  result.setKey(getKey());
  for(int i = 0; i < getNumberOfChildren(); i++) {
    result.setChild(i, getChild(i).clone());
  }
  return result;
}

Notice that TreeNode<E> result = new TreeNode<E>(getNumberOfChildren()); causes a brand new TreeNode object to be allocated (creating a genuine copy), while result.setKey(getKey()); sets the key of result to refer to the same object as the key of the object on which clone() is invoked. Thus the key itself is not cloned.