Hi, I am trying to build a Quadtree data structure(or let's just say a tree) on the secondary memory(Hard Disk). I have a C++ program to do so and I use fopen to create the files. Also, I am using tesseral coding to store each cell in a file named with its corresponding code to store it on the disk in one directory. The problem is tha...
Hi, I'm using the Google Closure Library and goog.ui.tree in particular to build a tree structure GUI component. It works pretty well out of the box, but I'd like to add a few extra controls to each of the leaves (goog.ui.Checkboxes in particular). The problem is that Component.addChild has been overridden in BaseNode so that each add...
Hello. Consider a weighted graph G=(V,E,w). We are given a family of subsets of vertices V_i. A Steiner Forest is a forest that for each subset of vertices V_i connects all of the vertices in this subset with a tree. Example: only one subset V_1 = V. In this case a Steiner forest is a spanning tree of the whole graph. Example: a grap...
Hello! I am learning about recursion tree's and trying to figure out how the height of the tree is log b of n where n = 2 and one has 10 elements as input size. I am working with Merge sort. The number of times the split is done is the height of the tree as far as I understood, and the number of levels in the tree is height + 1. But ...
I have a basic Tree built in Flex. The Tree works fine. I'm attempting to get a list of all of the visible nodes. I know there is a Tree.openItems, but that does not suffice because (for example) if you open all the items in your tree and then close the root, the invisible opened items are still counted. I simply want a list of all...
I have worked on UVA 10410 Tree Reconstruction several days. But I can't get the correct answer unitl now. I have used an algorithm similar to the one which we always use to recovery a binary tree through the preorder traversal and the inorder traversal. But it can't work. Can anyone help me? Thanks in advance. ...
Hey, I have a graphical editor with GEF. It's possible to add objects from a palette. An Example what I mean is this: http://java-eclipse.info/IBM.Redbooks-Eclipse.Development.using.the.Graphical.Editing.Framework.and.the.Eclipse.Modeling.Framework/7823/images/fig166_01_0.jpg So, now I want add a different possibility to display the con...
I can't figure out how to write a Binary Search Tree to file recursively. I open a BufferWriter with the file to wrtie too, in the Tree class. I then send the BufferWriter to the Node class to traverse the tree inorder and write to file. But it doesn't work. public void write(String filePath) { if(root != null) { try { Buffe...
I have portfolio table with portoflio_id and parent_portfolio_id and I have user table now some users may have access to all portfolios, or selective portfolios or depending on group, everything under a portfolio tree. can someone suggest a good schema or any existing framework ...
I'm looking for a good way to store and use hierarchical (parent/child) data in Django. I've been using django-mptt, but it seems entirely incompatible with my brain - I end up with non-obvious bugs in non-obvious places, mostly when moving things around in the tree: I end up with inconsistent state, where a node and its parent will disa...
Hello. Suppose I have such chunk of a sentence: (NP (NP (DT A) (JJ single) (NN page)) (PP (IN in) (NP (DT a) (NN wiki) (NN website)))) At a certain moment of time I have a reference to (JJ single) and I want to get the NP node binding A single page. If I get it right, that NP is the parent of the node, A and page a...
I'm trying to improve my current algorithm for the 8 Queens problem, and this is the first time I'm really dealing with algorithm design/algorithms. I want to implement a depth-first search combined with a permutation of the different Y values described here: http://en.wikipedia.org/wiki/Eight_queens_puzzle#The_eight_queens_puzzle_as_an_...
Hi, This project that I'm working on requires that an expression tree be constructed from a string of single digit operands and operators both represented as type char. I did the implmentation and the program up to that point works fine. I'm able to print out the inorder, preorder and postorder traversals in the correct way. The last ...
I'm capturing a right click event to show a context menu. What I haven't been able to figure out, is how to make the right click actually select the TreeItem, prior to showing of context menu. All help is appreciated. private Tree tree = new Tree() { @Override public void onBrowserEvent(Event event) { if (event.getTypeInt()...
I'm a big fan of JGraphT, a Java library for graphs. Could anyone recommend a similar Java library for trees? Preferrably FOSS. What I need is a good API, preferrably typesafe with generics which allows modelling different kinds of trees (with some user data attached to verticies/edges) and run different algorithms and operations on the...
I have a structure for a tree and I want to print the tree by levels. data Tree a = Nd a [Tree a] deriving Show type Nd = String tree = Nd "a" [Nd "b" [Nd "c" [], Nd "g" [Nd "h" [], Nd "i" [], Nd "j" [], Nd "k" []]], ...
Hi all, I'm trying to implement a HashMap-based tree that'd support O(1) subtree lookup for a given root key. To that goal, I'm trying to do the following: scala> type Q = HashMap[Char, Q] <console>:6: error: illegal cyclic reference involving type Q type Q = HashMap[Char, Q] ^ So the question is, is...
Is it possible to create a "tree resolver" in SQL? I have a table: ID Name Parent 1 a 2 b 1 3 c 1 4 d 3 Now I want a SQL query that returns: ID PATH 1 /a 2 /a/b 3 /a/c 4 /a/c/d Is this possible with SQL? It would make many things easier for me. Any help would really be appreciated! ...
There are tons of examples of using the RecursiveIterator to flatten a tree structure.. but what about using it to explode a tree structure? Is there an elegant way to use this, or some other SPL library to recursively build a tree (read: turn a flat array into array of arbitrary depth) given a table like this: SELECT id, parent_id, na...
I'm having a huge block trying to understand "trees" while making a Tic-Tac-Toe bot. I understand the concept, but I can't figure out to implement them. Can someone show me an example of how a tree should be generated for such a case? Or a good tutorial on generating trees? I guess the hard part is generating partial trees. I know how ...