recursion

Are variables shared in recursive functions

I'm trying to calculate the number of success cases within a recursive function in C#, but I'm astonished by the fact that my variable is shared between all the function calls! [update 2] More than strange this time. doing so i = i + validTreesFun(tree.Nodes, newWords.ToList()) ; resets i to 0 doing this i = validTreesFun(tree.Nod...

Scala list recursion performance

This question is about the way that Scala does pattern matching and recursion with lists and the performance thereof. If I have a function that recurses over a list and I do it with matching on a cons, for example something like: def myFunction(xs) = xs match { case Nil => Nil case x :: xs => «something» myFunction(xs) } in Hask...

How to make this code handle big inputs more efficiently?

Hey. I know this is not a 'refactor my code' site but I made this little piece of code which works perfectly fine with moderately sized input but it's problematic with string of size, say, over 2000. What it does - it takes a string of numbers as a parameter, and it returns the number of ways it can be interpreted as a string of letters...

LeftOuterJoin with same table - don't know how to distinguish them

Hi, I would like to make a LeftOuterJoin between one table and same table, but dont know how to make the distinguish them... SubSonic.SqlQuery q = new Select(). From(TABLE.Schema). LeftOuterJoin<TABLE>(); This returns me the error: The objects "dbo.TABLE" and "dbo.TABLE" in the FROM clause have the same exposed names....

F# forward type declarations

Hello everybody, I stumbled across this problem in F#. Suppose, I want to declare two types that reference each other: type firstType = | T1 of secondType //................ type secondType = | T1 of firstType //................ How do I do that, so the compiler does not generate an error? ...

Grouping and sorting algorithm help

Lets say I have a million people objects that, when evaluated using person1.Matches(person2); return true or false. I want to put them into groups. These groups are made by any one person being a match with any other person in the group. So any person from one group will NOT be a match with any person from another group. Any person in...

Call a function lower in the script from a function higher in the script

Hello, I'm trying to come up with a way to make the computer do some work for me. I'm using SIMD (SSE2 & SSE3) to calculate the cross product, and I was wondering if it could go any faster. Currently I have the following: const int maskShuffleCross1 = _MM_SHUFFLE(3,0,2,1); // y z x const int maskShuffleCross2 = _MM_SHUFFLE(3,1,0,2); //...

Parsing XMLList

There is an XMLList of items, each item has three properties: prop1, prop2, and prop3. There are two TextAreas, t1 and t2. t1 displays the XMLList.toString t2 is blank There are two buttons: Show and Clear. When you click Show, the following should happen: For each item in the XMLList, if prop3 is false and prop1 is "BB", then add that ...

Recursive menu builder with c#

Trying to build a recursive html menu using c#. The html structure I need is as follows: <ul> <li>Office</li> <li>Home <ul> <li>Beds</li> <li>Desks</li> </ul> </li> <li>Outdoor <ul> <li>Children <ul> <li>Playsets</li> </ul> </li> ...

PHP mkdir( $recursive = true ) skips last directory

I've got the following piece of code on a PHP 5.2.4 (no safe_mode) linux server: mkdir( $path, 0777, true ); when I enter a path like: '/path/to/create/recur/ively/' all directories are created axcept for the last one... when I add another directory like: '/path/to/create/recur/ively/more/' again, all paths are created except ...

Recursively PUT files to a remote server using FTP

I'm currently in a situation where I have very limited access to a server, but need to upload and download a significant amount of files contained within a single directory structure. I don't have SSH access, so I can't use SCP - and rsync isn't an option either unfortunately. I'm currently using ncftpput, which is great but seems to b...

Wordpress recursion through comments

Hi, I have edited my theme in Wordpress to show the 20 most recent comments to each post on the post list. Works fine and all. However I have nested comments enabled on my WP and would like to show nesting within the 20 recent comments. That is being if a comment is a reply to another comment which is in the recent 20 comments then nes...

A recursive remove directory function for PHP?

I am using PHP to move the contents of a images subfolder GalleryName/images/ into another folder. After the move, I need to delete the GalleryName directory and everything else inside it. I know that rmdir() won't work unless the directory is empty. I've spent a while trying to build a recursive function to scandir() starting fr...

Python recursive program to prime factorize a number

I wrote the following program to prime factorize a number: import math def prime_factorize(x,li=[]): until = int(math.sqrt(x))+1 for i in xrange(2,until): if not x%i: li.append(i) break else: #This else belongs to for li.append(x) print li #First print state...

Unnesting parentheses in Lisp

I want to write code (using recursive function) to unnest the parentheses in a LIST in Lisp language. Example: (unnest '(1 (2 (3)) (4 5))) ==> (1 2 3 4 5) Thanks. Any help is appreciated! ...

How to recursively create a multidimensional array?

I am trying to create a multi-dimensional array whose parts are determined by a string. I'm using . as the delimiter, and each part (except for the last) should be an array ex: config.debug.router.strictMode = true I want the same results as if I were to type: $arr = array('config' => array('debug' => array('router' => array('strictM...

How to recursively search through self-referential subtopics?

If I have a self-referential Topic class and I want to recursively loop through all of my subtopics, what would be a good Ruby way to do that: @category.topics.all(:parent_id => topic.id).each do |subtopic| subtopic.delete_tags @category.topics.all(:parent_id => subtopic.id).each do |subsubtopic| subsubtopic.delete_tags ...

difference between structural recursion and accumulative recursion

I have been learning scheme and I like to know the difference between the two. Thanks. ...

The best way to conditionally execute a function?

Yes, I know the wording is hard to understand, but this is something that bugs me a lot. On a recent project, I have a function that recurses, and there are a number of conditions that would cause it to stop recursing (at the moment three). Which of the situations would be optional? (I.E. best performance or easiest maintenance). 1) ...

Php: Generate ul-li tree from active directory results

I've got a result set from adLDAP of the form OU=LEAF1,OU=PARENT1,OU=ROOT,DC=datacenter,DC=local OU=PARENT1,OU=ROOT,DC=datacenter,DC=local OU=ROOT,DC=datacenter,DC=local OU=LEAF2,OU=CHILD,OU=PARENT2,OU=ROOT,DC=datacenter,DC=local OU=CHILD,OU=PARENT2,OU=ROOT,DC=datacenter,DC=local OU=PARENT2,OU=ROOT,DC=datacenter,DC=local Where each li...