private TreeNode getSuccessor(TreeNode node)
{
TreeNode parentOfSuccessor = node;
TreeNode successor = node;
TreeNode current = node.GetRight();
while (current != null)
{
parentOfSuccessor = successor;
successor = current;
current = current.GetLeft();
}
if (successor != node.GetRight())
{
parentOfSuccessor.SetLeft(successor.GetRight());
successor.SetRight(node.GetRight());
}
return(successor);
}
public void Delete(int data)
{
TreeNode parent = this.root;
TreeNode current = this.root;
bool isleft = false;
if (root == null)
{
return;
}
while (current != null && current.GetData() != data)
{
parent = current;
if (current.GetData() < data)
{
current = current.GetLeft();
isleft = true;
}
else
{
current = current.GetRight();
isleft = false;
}
}
if (current == null)
{
return;
}
if (current.GetRight() == null && current.GetLeft() == null)
{
if (root == current)
{
root = null;
}
else
{
if (isleft == true)
{
current.SetLeft(null);
}
else
{
current.SetRight(null);
}
}
}
else if (current.GetLeft() == null)
{
if (root == current)
{
root = current.GetRight();
}
else if (isleft)
{
parent.SetLeft(current.GetRight());
}
else
{
parent.SetRight(current.GetRight());
}
}
else if (current.GetRight() == null)
{
if (root == current)
{
root = current.GetLeft();
}
else if (isleft)
{
parent.SetLeft(current.GetLeft());
}
else
{
parent.SetRight(current.GetLeft());
}
}
else
{
TreeNode successor = getSuccessor(current);
if (current == root)
{
root = successor;
}
else if (isleft)
{
parent.SetLeft(successor);
}
else
{
parent.SetRight(successor);
}
successor.SetLeft(current.GetLeft());
}
}