我在尝试实现的 AVL 树中遇到了一些编译错误。有什么东西让整个枚举器失望了。在我尝试实现一个辅助类之前，它编译得很好。我认为这与 BTNode 本身是一个私有嵌套类有关，但尝试将其公开只是为了看看会发生什么，但无济于事。
我对此有点难过，不应该进行任何转换。
任何帮助将不胜感激。
这是源代码，我已经注意到编译错误的位置，并分解了不同的嵌套类以便于阅读。
class AVLTree<TKey, TValue> : IEnumerable<TKey> where TKey : IComparable<TKey>
{
#region nested classes
节点类——
#region BTNode class
private class BTNode<TKey, TValue> where TKey : IComparable<TKey>
{
#region class variables
public TValue data;
public TKey key;
public int height;
public int balFactor;
public BTNode<TKey, TValue> up;
public BTNode<TKey, TValue> left;
public BTNode<TKey, TValue> right;
#endregion
#region con/destructors
//Key and value, constructor for very first node.
public BTNode(TKey new_key, TValue new_data)
{
key = new_key;
data = new_data;
height = 1;
balFactor = 0;
}
//Normal use constructor after initial
//has been made.
public BTNode(TKey new_key, TValue new_data, BTNode<TKey, TValue> new_up)
{
key = new_key;
data = new_data;
up = new_up;
height = 1;
balFactor = 0;
}
#endregion
}
#endregion
枚举器辅助类——
#region Enumerator class
private class AVLEnumerator<TKey,TValue> : IEnumerator<TKey> where TKey : IComparable<TKey>
{
#region class variables
private AVLTree<TKey, TValue> AVLTreeEnum;
private BTNode<TKey, TValue> current;
#endregion
#region con/destructors
public AVLEnumerator(AVLTree<TKey, TValue> toEnumerate)
{
AVLTreeEnum = toEnumerate;
current = null;
}
#endregion
#region interface methods
//interface method to move to the next
//node.
public bool MoveNext()
{
BTNode<TKey, TValue> sendMe;
//If current is null, it's at start of tree,
//set current to leftmost node in left subtree of root.
if (current == null)
{
/* error below on 'sendMe =' line--
* Cannot implicitly convert type
* 'BSTs.AVLTree<TKey,TValue>.BTNode<TKey,TValue> ' to
* 'BSTs.AVLTree<TKey,TValue>.BTNode<TKey,TValue> '
*/
sendMe = AVLTreeEnum.root;
/* two errors on 'current =' line--
* The best overloaded method match for
* 'BSTs.AVLTree<TKey,TValue>.GetLeftMost
* (BSTs.AVLTree<TKey,TValue>.BTNode<TKey,TValue>)'
* has some invalid arguments
*
* and
*
* Argument 1: cannot convert from
* 'BSTs.AVLTree<TKey,TValue>.BTNode<TKey,TValue>' to
* 'BSTs.AVLTree<TKey,TValue>.BTNode<TKey,TValue>'
*/
current = AVLTreeEnum.GetLeftMost(sendMe);
}
else
{
//If we can go right from current, get leftmost node
//of current.rights left subtree.
if (current.right != null)
{
sendMe = current.right;
/* two errors on 'current =' --
* The best overloaded method match for
* 'BSTs.AVLTree<TKey,TValue>.GetLeftMost
* (BSTs.AVLTree<TKey,TValue>.AVLNode<TKey,TValue>)'
* has some invalid arguments
*
* and
*
* Argument 1: cannot convert from
* 'BSTs.AVLTree<TKey,TValue>.AVLNode<TKey,TValue>'
* to 'BSTs.AVLTree<TKey,TValue>.AVLNode<TKey,TValue>'
*/
current = AVLTreeEnum.GetLeftMost(sendMe);
}
else
{
//Move up until we find a value larger than current.
TKey currentValue = current.key;
while (current != null)
{
current = current.up;
if (current != null)
{
if (current.key.CompareTo(currentValue) >= 0)
{
break;
}
}
}
}
}
return (current != null);
}
//Interface method to reset enumeration
public void Reset()
{
current = null;
}
//Interface property to return current key
public TKey Current
{
get
{
if (current == null)
{
throw new InvalidOperationException(
"Enumerator got a null");
}
return current.key;
}
}
//interface non-generic method
Object System.Collections.IEnumerator.Current
{
get { return this.Current; }
}
//interface method, must have a dispose.
public void Dispose()
{ }
#endregion
}
#endregion
#endregion
--
#region class variables
private BTNode<TKey, TValue> root;
private int size;
#endregion
#region properties
public int Size
{ get { return size; } }
#endregion
#region con/destructors
public AVLTree()
{ size = 0; }
~AVLTree()
{
root = null;
}
#endregion
--
#region interface implementation
//Interface for IEnumerable<T>
public IEnumerator<TKey> GetEnumerator()
{
return new AVLEnumerator<TKey,TValue>(this);
}
//Interface for IEnumerable. Must be included w/ Ienumerable<T>
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return this.GetEnumerator();
}
#endregion
安...
//This method will get the leftmost node of it's left subtree.
//used by the Enumeration class.
private BTNode<TKey, TValue> GetLeftMost(BTNode<TKey, TValue> currentNode)
{
while (currentNode.left != null)
{
currentNode = currentNode.left;
}
return currentNode;
}