//Function for finding a movie in the tree
public MovieTreeNode Find(Movie movie)
{
string movieTitle = movie.getTitle();
MovieTreeNode currentNode = this;
//While there is still a node to search in
while (currentNode != null)
{
//If the movie it's searching for is the current node, return the node
if (string.Compare(movieTitle, currentNode.movie.getTitle()) == 0 && isDeleted == false)
{
return(currentNode);
}
//If the movie is less than the current node and the left subtree is not empty, search the left subtree
else if (string.Compare(movieTitle, currentNode.movie.getTitle()) < 0 && leftNode != null)
{
return(leftNode.FindRecursive(movie));
}
//Otherwise search the right subtree if it's not empty
else if (rightNode != null)
{
return(rightNode.FindRecursive(movie));
}
//The movie doesn't exist in the tree
else
{
return(null);
}
}
return(null);
}
//Function for inserting a movie object into the tree
public void Insert(Movie movieAdd)
{
string movieTitileAdd = movieAdd.getTitle();
//If the movie to be added is greatter than the current node
if (string.Compare(movieTitleAdd, movie.getTitle()) >= 0)
{
if (rightNode == null)
{
//Movie is added to the right of the parent node if the right subtree is empty
rightNode = new MovieTreeNode(movieAdd);
}
else
{
//If the right subtree isn't empty, go to the right subtree
rightNode.Insert(movieAdd);
}
}
//If the movie to be added is less than the current node
else
{
//If the left subtree is empty, add the movie to the left subtree
if (leftNode == null)
{
leftNode = new MovieTreeNode(movieAdd);
}
//If it isn't empty, go to the left subtree
else
{
leftNode.Insert(movieAdd);
}
}
}
private MovieTreeNode Replacement(MovieTreeNode currentNode)
{
MovieTreeNode replacementParent = currentNode;
MovieTreeNode replacement = currentNode;
MovieTreeNode current = currentNode;
//Finding the last left node of the right node
while (current != null)
{
replacementParent = replacement;
replacement = current;
current = current.LeftNode;
}
//If the right node of the node to be deleted has atleast one left node
if (replacement != currentNode.RightNode)
{
replacementParent.LeftNode = replacement.RightNode;
//Moving the right node of the node to be deleted to the right of the replacement node
replacement.RightNode = currentNode.RightNode;
}
//Moving the left child of the node to be deleted to the left child of the deleted nodes right child
replacement.LeftNode = currentNode.LeftNode;
return(replacement);
}
//Function for inserting node into tree
public void Insert(Movie movieAdd)
{
if (root != null)
{
root.Insert(movieAdd);
}
else
{
//Movie is added as the root node
root = new MovieTreeNode(movieAdd);
}
}
public int Remove(string movieTitle)
{
//Setting the the current node to the root
MovieTreeNode current = root;
//Setting the parent node to the root
MovieTreeNode parent = root;
bool leftChild = false;
//If the tree is empty, then nothing happens
if (current == null)
{
return(-1);
}
//While the current search node does not equal the movie title we're searhing for and the current search node is not empty
while (current != null)
{
parent = current;
if (string.Compare(movieTitle, current.Movie.getTitle()) == 0)
{
break;
}
//If the movie title we're searching for is less than the current node than we'll search the left side of the tree
else if (string.Compare(movieTitle, current.Movie.getTitle()) < 0)
{
//Setting the current node to the left node
current = current.LeftNode;
leftChild = true;
}
//Otherwise we'll search the right side of the tree
else
{
//Setting the current node to the right node
current = current.RightNode;
leftChild = false;
}
}
//If the current node is empty, then nothing happens
if (current == null)
{
return(-1);
}
//If the movie title to be deleted is a leaf
if (current.RightNode == null && current.LeftNode == null)
{
//If the movieTitle to be deleted is the root node
if (current == root)
{
root = null;
}
else
{
//If the current node is a left child
if (leftChild)
{
//Removing the movie from the tree
parent.LeftNode = null;
}
else
{
//Removing the movie from the tree
parent.RightNode = null;
}
}
}
//If the node to be deleted only has a left child
else if (current.RightNode == null)
{
//If the node to be deleted is the root
if (current == root)
{
//Move the left child to the root
root = current.LeftNode;
}
else
{
//If node to be deleted is a left child
if (leftChild)
{
//Setting the parents left node to the current node
parent.LeftNode = current.LeftNode;
}
else
{
parent.RightNode = current.LeftNode;
}
}
}
//If the node to be deleted only has a right child
else if (current.LeftNode == null)
{
//If the node to be deleted is the root
if (current == root)
{
//Setting the root to the right child
root = current.RightNode;
}
else
{
if (leftChild)
{
//Setting the parents left node to the current node
parent.LeftNode = current.RightNode;
}
else
{
//Setting the parents right node to the current node
parent.RightNode = current.RightNode;
}
}
}
//If the node to be deleted has a left and right child
else
{
MovieTreeNode replacement = Replacement(current);
//If the node to be deleted is the root node
if (current == root)
{
root = replacement;
}
//If the node to be deleted is a left child
else if (leftChild)
{
parent.LeftNode = replacement;
}
//If the node to be deleted is a right child
else
{
parent.RightNode = replacement;
}
}
return(1);
}
