recursive-datastructures

Confusing [...] List in Python: What is it?

So I was writing up a simple binary tree in Python and came across [...] I don't believe this to be related to the Ellipsis object, more it seems to have something to do with an infinity loop (due to Python's shallow copy?). The source of this infinity loop and why it doesn't get expanded while expanding when accessed is something I'm c...

How do I marshall a recursive struct to c sharp?

Hi, I have an unmanaged struct I'd like to marshal to c sharp that looks basically like this: struct MyStruct{ /* ... some stuff ... */ int numChilds; MyStruct *childs; } I believe that I have to write a custom marshaller but I'm not sure on how to proceed. ...

populate treeview from a list of path

Hi, I'm trying to populate a treeview from a list of folder path, for example: C:\WINDOWS\addins C:\WINDOWS\AppPatch C:\WINDOWS\AppPatch\MUI C:\WINDOWS\AppPatch\MUI\040C C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727 C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\MUI C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\MUI\0409 with an ouput ...

Generating all possible trees of depth N?

I have several different types of tree nodes, each of which may have anywhere from 0 to 5 children. I'm trying to figure out an algorithm to generate all possible trees of depth <= N. Any help here? I'm having trouble figuring out how to recursively walk the tree given that each change I make to a node may expose new subtrees (or remo...

How CSS and DOM is implemented in the browser?

This is a pretty academic question. I'm wondering how the browser is implemented as in what data structure or algorithm is used to map a CSS selector to a particular DOM element. Is it accomplished through a hash table? How does DOM child node knows that the style applied to parent also applies to itself etc. I've been looking at Moz...

Find shortest path between two webpages

I need to find the shortest distance between two Wikipedia pages (in "hops") I have a method to extract all the internal wiki links on a page I know the start destination and the end destination but I'm coming up blank on how to extract the hops from the data so far ive been using the link extraction method to populate a dictionary wi...

What is an infinite scaleless quadtree called?

2D spatial indexing question: What do you call a data structure that is essentially an infinite* quadtree whose nodes contain neither absolute coordinates nor absolute scales -- in which the coordinate system of each node has been normalized to the unit square (0,0)-(1,1), and in which the top-level node is not fixed absolutely? It's a...

Java Generics Type Safety warning with recursive Hashmap

Hi, I'm using a recursive tree of hashmaps, specifically Hashmap map where Object is a reference to another Hashmap and so on. This will be passed around a recursive algorithm: foo(String filename, Hashmap<String, Object> map) { //some stuff here for (Entry<String, Object> entry : map.entrySet()) { //type warning th...

Display `pretty output` of directory content from array

Hi, I'm using the following code to get an array of directories and their sub-directories where each contain file type extension: png. It works great but I need to be able to output the results of the array in a list style format e.g. * Test -> test2.png -> test1.png * subfolder -> test3.png * sub sub folder -> test...

What do I use for a max-heap implementation in Python?

Python includes the heapq module for min-heaps, but I need a max heap. What should I use for a max-heap implementation in Python? ...

Checking whether some object has been already tested

I have a script that is intended to check whether some value (e.g. option or function argument) matches some model. I want my script to be able to check recursive data structures. So the question is: is there more efficient way then iterating over some list that contains references to already checked Lists and Dictionaries. Example code:...

How to create a recursive data structure value in (functional) F#?

How can a value of type: type Tree = | Node of int * Tree list have a value that references itself generated in a functional way? The resulting value should be equal to x in the following Python code, for a suitable definition of Tree: x = Tree() x.tlist = [x] Edit: Obviously more explanation is necessary. I am trying to learn...