public BinaryTree(int key, int value )
{
Key = key;
Value = value;
Left = null;
Right = null;
}
/// <summary>
/// For the Value, delete the node from the tree.
/// </summary>
/// <param name="Cursor">Root of the Tree</param>
/// <param name="i">Value to be deleted</param>
/// <returns></returns>
///
public static bool Delete( ref BinaryTree Cursor, int i )
{
/*
* Find the node for the Value, we will come out
* of this loop only after finding the Value or reaching at
* end of tree.
*
*/
while (Cursor != null) {
if (Cursor.Key == i ) {
break; //got the Value- Get out of the loop
}
/* Is the Value in question more then Node Value
* Then go towards Right
*/
if (i > Cursor.Key ) {
if (Cursor.Right != null)
Cursor = Cursor.Right ;
else
return false; /* Oouch - going back did't find the Value */
}
else {
/*
* Value in Question is smaller
* We are heading towards Left
*/
if (Cursor.Left != null)
Cursor = Cursor.Left ;
else
return false; //going back did't find the Value
}
}
/* got the node only if it is NOT null, if it is null
* get lost
*/
if (Cursor == null) return false ;
/*
* Is it a leave
*/
if (Cursor.Left == null && Cursor.Right == null ) {
/* Simply remove it */
Cursor.Key = 0;
return true;
}
if (Cursor.Left == null ) {
/* Case 1
* node does't have a left child, then simpley promote the right
* node to root.
*
* NOTE: Must keep the right node in a temp Node
* Cursor.Right = Cursor.Right.Right
* Moves the whole Cursor, altogether
*
* pittsburgh Seattle
* / \ / \
* null Seattle => / \
* / \ Left Right
* Left Right
*/
BinaryTree TempNode = Cursor.Right ;
Cursor.Key = TempNode.Key ;
Cursor.Right.Key = 0 ; //Mark it for deletion
Cursor.Right = TempNode.Right ;
if (TempNode.Left != null)
Cursor.Left = TempNode.Left ;
else
Cursor.Left = null;
return true;
}
else {
/* case 2
* Node *DOES* have a LEFT child, find the MAX RIGHT child
* of LEFT NODE and then make that Node as root
*
* To Delete A
* Get the biggest Node from the Right hand side
*
* A R2
* / \ / \
* / \ / \
* L1 R1 => L1 R1
* / \ / \ / / \
* L2 R2 RL1 RR2 L2 RL1 RR2
*/
//Got the Node in the Question, keep it in Temp
BinaryTree _Node = Cursor;
//Get on the Left Node
Cursor = Cursor.Left ;
//Find out Max Right
BinaryTree BigRNode = GetMaxRight ( ref Cursor );
_Node.Key = BigRNode.Key ;
BigRNode.Key = 0; //Mark it for deletion
return true;
}
}
/// <summary>
/// Transverse in the right direction and get the biggest node
/// </summary>
/// <param name="node">Node from where to start the search</param>
/// <returns>
/// return the BinaryTree Node which is biggest by the virtue of
/// binary tree
/// </returns>
///
private static BinaryTree GetMaxRight(ref BinaryTree Cursor )
{
//As soon as the function gets a Left null of a Node
//it returns the node.
if (Cursor == null) return null;
if (Cursor.Right != null) {
Cursor = Cursor.Right;
GetMaxRight (ref Cursor);
}
return Cursor;
}
/// <summary>
/// Prints the Btree in Backward In-Order traversal
/// </summary>
/// <param name="root">root node</param>
/// <param name="depth">should be one 1</param>
/// <param name="Tab">if true puts tab</param>
///
public static void Print( BinaryTree root, int depth, bool Tab )
{
if (root != null) {
Print (root.Right, depth + 1, Tab );
int i = 0;
while ( i++ < depth && Tab ) {
Console.Write (" ");
}
Console.WriteLine (root.Key );
Print (root.Left, depth + 1, Tab );
}
}
public static void MakeNull(ref BinaryTree root)
{
if (root != null ) {
if ( root.Key == 0 ) {
root = null ;
return;
}
MakeNull(ref root.Left );
MakeNull(ref root.Right );
}
}
/// <summary>
/// Inserts the Value in Binary Tree.
/// </summary>
/// <param name="root">Root of the Binary Tree.</param>
/// <param name="key">Value to be inserted.</param>
public static void InsertValue( ref BinaryTree root, int key, int value )
{
BinaryTree Cursor = root;
/*
* Remain in loop - keep transversing the tree
* till find out the proper node or fall of the tree
*/
while (Cursor != null) {
if (key <= Cursor.Key ) {
/* if i is smaller then the cursor Value
* GO LEFT
*/
if (Cursor.Left != null)
Cursor = Cursor.Left ;
else
break;
}
else {
if (Cursor.Right != null)
Cursor = Cursor.Right;
else
break;
}
}
/* Reached to the Last node */
if ( key <= Cursor.Key ) {
/* if i is small or equal to node Value, add it to the left */
BinaryTree b = new BinaryTree (key, value);
Cursor.Left = b;
}
else {
BinaryTree b = new BinaryTree (key, value);
Cursor.Right = b;
}
return;
}