public void DeleteByCopying(int value)
{
TreeNode curr = Root;
TreeNode parent = null;
while (curr != null)
{
if (curr.Value == value)
break;
parent = curr;
if (curr.Value > value)
curr = curr.Left;
else
curr = curr.Right;
}
if (curr == null)
return;
if (curr.Left == null && curr.Right == null)
{
if (parent != null)
{
if (parent.Value > curr.Value)
parent.Left = null;
else
parent.Right = null;
}
else
Root = null;
curr = null;
}
else
{
if (curr.Left == null)
{
if (parent != null)
{
if (parent.Value > curr.Value)
parent.Left = curr.Right;
else
parent.Right = curr.Right;
}
else
parent = curr.Right;
curr = null;
}
else if (curr.Right == null)
{
if (parent != null)
{
if (parent.Value > curr.Value)
parent.Left = curr.Left;
else
parent.Right = curr.Left;
}
else
parent = curr.Left;
curr = null;
}
else
{
//find the rightmost node
TreeNode tmp = curr.Left;
TreeNode tmpParent = curr;
while (tmp.Right != null)
{
tmpParent = tmp;
tmp = tmp.Right;
}
curr.Value = tmp.Value;
if (tmpParent != curr)
tmpParent.Right = tmp.Left;
else
tmpParent.Left = tmp.Left;
tmp = null;
}
}
}
public void AddNode(int value)
{
TreeNode newNode = new TreeNode(value);
addNode(Root, newNode);
}
private void dfsPreorder(TreeNode node)
{
if (node == null)
return;
Console.WriteLine(node.Value);
dfsPreorder(node.Left);
dfsPreorder(node.Right);
}
private void addNode(TreeNode parent, TreeNode child)
{
if (parent == null)
{
Root = child;
return;
}
if (parent.Value == child.Value)
return;
if (parent.Value > child.Value)
{
if (parent.Left == null)
parent.Left = child;
else
addNode(parent.Left, child);
}
else
{
if (parent.Right == null)
parent.Right = child;
else
addNode(parent.Right, child);
}
}
