// удалить из дерева корень root узел со значением data
public void DeleteNode(int data)
{
TreeNode node = FindNode(root, data);
if (node == null)
{
return;
}
TreeNode left = node.left;
TreeNode right = node.right;
TreeNode parent = node.parent;
if (right == null)
{
if (parent != null)
{
parent.replaceChild(node, left);
}
else
{
root = left;
}
return;
}
if (parent != null)
{
parent.replaceChild(node, right);
}
else
{
root = right;
}
if (left == null)
{
return;
}
TreeNode leastRightLeft = findMinNode(right);
leastRightLeft.left = left;
}