Solved

binary tree

Posted on 1998-11-29
13
301 Views
Last Modified: 2013-11-15
i need a code for removing a node from the tree, considerating all cases. function suld be recursive.
very basic c++ - no templates , very close to c language , but with treenode class that holds the tree, and node class
that holds only the data. i hope it's not too much to ask. thank you very much for your help!
0
Comment
Question by:liorliat
  • 9
  • 4
13 Comments
 

Author Comment

by:liorliat
ID: 1178784
Edited text of question
0
 

Author Comment

by:liorliat
ID: 1178785
node class has 3 node pointers - left , right , parent.
0
 

Author Comment

by:liorliat
ID: 1178786
node class has 3 node pointers - left , right , parent.
0
Backup Your Microsoft Windows Server®

Backup all your Microsoft Windows Server – on-premises, in remote locations, in private and hybrid clouds. Your entire Windows Server will be backed up in one easy step with patented, block-level disk imaging. We achieve RTOs (recovery time objectives) as low as 15 seconds.

 

Author Comment

by:liorliat
ID: 1178787
node class has 3 node pointers - left , right , parent.
0
 
LVL 1

Accepted Solution

by:
Booth882 earned 100 total points
ID: 1178788
do you want to remove a node from anywhere or one from the outermost branches (ie one with no Right or Left pointer)?  to remove one from the outermost branches you could say

node * CurrentNode = trunk // trunk is the base node in the tree

while(CurrentNode->Left || CurrentNode->Right)
{
    if(CurrentNode->Left)
        CurrentNode = CurrentNode->Left;
    else
        CurrentNode = CurrentNode->Right;
}

if(CurrentNode->ParentNode->Left == CurrentNode)
    CurrentNode->ParentNode->Left = 0;
else
    CurrentNode->ParentNode->Right = 0;

EraseNode(CurrentNode);

I think this is what you want to do, because to remove a node from an arbitrary location would take the removal of all the nodes it is a parent and grandparent etc to.  you could do that though too.  all it would take would be to take the above algorithm and repeat until the node you want to remove has no branches coming from it, ie

if(RemovalNode->Right == 0 && RemovalNode->Left == 0)

and instead of using the trunk of the whole tree to initialize CurrentNode use the node you want to remove, like this

void RemoveNode(node * RemovalNode)
{
    while(RemovalNode->Right != 0 && RemovalNode->Left != 0)
    {
        node * CurrentNode = RemovalNode;

        while(CurrentNode->Left || CurrentNode->Right)
        {
            if(CurrentNode->Left)
                CurrentNode = CurrentNode->Left;
            else
                CurrentNode = CurrentNode->Right;
        }

        if(CurrentNode->ParentNode->Left == CurrentNode)
            CurrentNode->ParentNode->Left = 0;
        else
            CurrentNode->ParentNode->Right = 0;

        EraseNode(CurrentNode); // however you are doing this,
                                // possibly delete CurrentNode;?
    }
}

that should do it.  let me know if you have any questions.
0
 
LVL 1

Expert Comment

by:Booth882
ID: 1178789
hey liorliat?  you still there?...
0
 

Author Comment

by:liorliat
ID: 1178790
thank you very much for you'r answer.
i'm afraid that it was'nt exactly what i ment. i want to delete an arbitrary node from the tree, and keep the property of a binary tree.
by now, i wrote the  functions to do the next:
1) find the predecessor of a node,by sending the pointer of the node.
2) find the successor.
3) find a node in the tree by getting its data (an integer in my qestion case)
4) find min and max from a node (functions gets the pointer to the node)
all functions returns a pointer to the node found , or NULL .
now,using all this function,and having right left and parent pointer in each node,how do i delete an arbitrary node,keeping the property of a binary tree still?
0
 

Author Comment

by:liorliat
ID: 1178791
thank you very much for you'r answer.
i'm afraid that it was'nt exactly what i ment. i want to delete an arbitrary node from the tree, and keep the property of a binary tree.
by now, i wrote the  functions to do the next:
1) find the predecessor of a node,by sending the pointer of the node.
2) find the successor.
3) find a node in the tree by getting its data (an integer in my qestion case)
4) find min and max from a node (functions gets the pointer to the node)
all functions returns a pointer to the node found , or NULL .
now,using all this function,and having right left and parent pointer in each node,how do i delete an arbitrary node,keeping the property of a binary tree still?
0
 

Author Comment

by:liorliat
ID: 1178792
thank you very much for you'r answer.
i'm afraid that it was'nt exactly what i ment. i want to delete an arbitrary node from the tree, and keep the property of a binary tree.
by now, i wrote the  functions to do the next:
1) find the predecessor of a node,by sending the pointer of the node.
2) find the successor.
3) find a node in the tree by getting its data (an integer in my qestion case)
4) find min and max from a node (functions gets the pointer to the node)
all functions returns a pointer to the node found , or NULL .
now,using all this function,and having right left and parent pointer in each node,how do i delete an arbitrary node,keeping the property of a binary tree still?(sorry th bother you again...)    :-)              
0
 
LVL 1

Expert Comment

by:Booth882
ID: 1178793
what do you mean by keep the property of a binary tree?  

could you clarify what you mean by 'property'?
0
 

Author Comment

by:liorliat
ID: 1178794
by saying "keep the property of binary tree" i mean that the tree would still be sorted as a binary tree after the removal of an arbitrary node.
please give me an answer as soon as possible,  i need it  7 hours from now !!!
thanks again.

0
 
LVL 1

Expert Comment

by:Booth882
ID: 1178795
the second algorithm I showed you would still keep it sorted as a binary tree.  it is necessary to delete all the nodes that spring from the removed node because otherwise you would have no connection to them and their memory would be lost, but after you are done it will still be a binary tree.  give it a try, it works! :)
0
 

Author Comment

by:liorliat
ID: 1178796
thanks a lot fo your quick response.
soory about the misunderstanding.
you SAVED me!
i'll be talking to you when i'll have another  ?  
it probebly wont take long...  :)
0

Featured Post

Three Reasons Why Backup is Strategic

Backup is strategic to your business because your data is strategic to your business. Without backup, your business will fail. This white paper explains why it is vital for you to design and immediately execute a backup strategy to protect 100 percent of your data.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article describes how to use the timestamp of existing data in a database to allow Tableau to calculate the prior work day instead of relying on case statements or if statements to calculate the days of the week.
Let’s list some of the technologies that enable smooth teleworking. 
The goal of the tutorial is to teach the user how to use functions in C++. The video will cover how to define functions, how to call functions and how to create functions prototypes. Microsoft Visual C++ 2010 Express will be used as a text editor an…
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.

774 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question