Comments on: Generic (n-ary) Tree in Java

By: Manoj Rajan

Manoj Rajan — Mon, 09 Jan 2012 11:54:24 +0000

Thanks, vivin.

It was helpful. Implementation was easy and understandable much faster.

By: vivin

vivin — Sun, 11 Dec 2011 19:42:05 +0000

@John Vorwald: Thanks!

By: vivin

vivin — Sun, 11 Dec 2011 19:40:57 +0000

@Fernando: The purpose of the "build" methods is to return a representation of the tree as a list in either preorder, or postorder form. The "buildWithDepth" returns a representation of the tree with the depths of the node as well, which is useful if you're trying to provide a graphical representation of the tree. In hindsight, I believe it would have been better to implement an iterator!

By: Fernando

Fernando — Sun, 11 Dec 2011 17:14:37 +0000

Hi,

Probably I`m missing the point but what is the real purpose of build* methods? I mean, except for testing, why I would use a List ? BTW, I don’t think that “build” is the correct name. Can you “build a generic tree” ?

My $,02.

Cheers,

–FM

By: John Vorwald

John Vorwald — Sun, 11 Dec 2011 12:48:19 +0000

Here are two additional routines to allow searching for data.

public List locateOccurances(T data) {
List< GenericTreeNode > occurances = new ArrayList();
if (root != null) {
occurances.addAll( locateOccurances(root, data) );
}
return occurances;
}

public List locateOccurances(GenericTreeNode node, T data) {
List< GenericTreeNode > occurances = new ArrayList();

if (node.data == data) {
occurances.add(node);
}
for (GenericTreeNode child:node.children) {
occurances.addAll( locateOccurances(child, data) );
}
return occurances;
}

By: miliardopiscrat

miliardopiscrat — Fri, 23 Sep 2011 23:14:42 +0000

class GenericTreeNode.java line 68, put there keyword @Override and see if it compile.

By: Maven project for Generic (n-ary) Tree in Java | Rough Book

Maven project for Generic (n-ary) Tree in Java | Rough Book — Wed, 25 May 2011 16:14:36 +0000

[...] Guus was kind enough to make a maven project for the Generic Tree. He also fixed an error in my equals method for the GenericTreeNode (I intended to do Object.equals(Object obj) but was doing GenericTreeNode.equals(GenericTreeNode obj). Since it’s a maven project, you can easily create a jar out of it and add it as a dependency to your project. You can download the project here. Thanks Guus! AKPC_IDS += "1405,";Popularity: unranked [?] Related PostsGeneric (n-ary) Tree in JavaCherryBlossomIntroducing CherryBlossomif-else in bAdkOdebAdkOde: An Esoteric LanguageJSTL, instanceof, and hasPropertyDuct-tape programmers are not heroesPerformance testing using The GrinderRunning the JavaFX 1.1 SDK on LinuxRunning the JavaFX 1.0 SDK on Linux Categories: Java, Programming and Development Tags: data structures, generic trees, java, k-ary trees, n-ary trees, programming, software engineering, trees (data structure) Comments (3) Trackbacks (0) Leave a comment Trackback [...]

By: vivin

vivin — Wed, 06 Apr 2011 16:39:26 +0000

@Akshay glad to be able to help

By: Akshay

Akshay — Fri, 01 Apr 2011 16:29:58 +0000

Hi Vivin,
Your Tree implementation was really useful for us in our compilers project for maintaining the relationship between various scopes in a program. Though we needed only a very small subset of Tree operations, your implementation provided a very good view into how to build an n-ary Tree in Java.
And like you said in your above post, I also needed the parent pointer in every node to traverse back from a node all the way upto the root.
Also, in line#69 in GenericTree.java, there is a redundant \i=0\ assignment. I guess you could remove that.

Thanks a lot

By: vivin

vivin — Sat, 12 Feb 2011 18:11:58 +0000

@jens It's funny you say that because I needed that very same functionality just yesterday! My current implementation does not offer that functionality, however it should be trivial to add. You just need a private property in GenericTreeNode:

private GenericTreeNode parent;

and in the addChild method, set the parent of the new child node to this.