Questions regarding efficient storing and representing data within a software application.
5
votes
1answer
974 views
Decision trees vs. Neural Networks
I'm implementing a machine learning structure to try and predict fraud on financial systems like banks, etc... This means that there is a lot of different data that can be used to train the model eg. ...
1
vote
2answers
100 views
Cataloging events, projects and tasks: Is SQL appropriate?
I have this idea for a database: it would hold everything I "need to remember", and allow future coding projects to access the information. These future projects include a day-planner and historical ...
1
vote
5answers
617 views
What Java data structure/design pattern best models this object, considering it would perform these methods?
Methods:
1. getDistance(CityA,CityB) // Returns distance between two cities
2. getCitiesInRadius(CityA,integer) // Returns cities within a given distance of another city
3. ...
5
votes
2answers
573 views
Writing a new programming language - when and how to bootstrap datastructures?
I'm in the process of writing my own programming language which, thus far, has been going great in terms of what I set out to accomplish. However, now, I'd like to bootstrap some pre-existing data ...
27
votes
4answers
2k views
Which algorithms/data structures should I “recognize” and know by name? [closed]
I'd like to consider myself a fairly experienced programmer. I've been programming for over 5 years now. My weak point though is terminology. I'm self-taught, so while I know how to program, I don't ...
6
votes
3answers
309 views
A deque based on binary trees
This is a simple immutable deque based on binary trees. What do you think about it? Does this kind of data structure, or possibly an improvement thereof, seem useful? How could I improve it, ...
5
votes
11answers
2k views
What are some good, simple examples for queues?
I'm teaching CS2 (Java and data structures), and am having some difficulty coming up with good examples to use when teaching queues. The two major applications I use them for are multithreaded message ...
17
votes
4answers
654 views
What is the definition of “Big Data”?
Is there one?
All the definitions I can find describe the size, complexity / variety or velocity of the data.
Wikipedia's definition is the only one I've found with an actual number
Big data ...
2
votes
1answer
205 views
List structures in memory
Could anyone give an overview of how list structures which are composed of a
head and a tail which references the rest of the list i.e linked list are represented in memory of the computer? Does the ...
7
votes
4answers
376 views
finding houses within a radius
During an interview I was asked given the following: A real estate application that lists all houses that are currently on the market (i.e., for sale) within a given distance (say for example the user ...
1
vote
1answer
184 views
Javascript: Safely upload a client data file
I'm (still) working on a template-based XML editing program. It's a GUI-based XML editor that only allows users to add certain tags and attributes based off the requirements. You can see the current ...
4
votes
1answer
320 views
Which data structure to represent a triangular undirected graph
I was wanting to create a graph similar to this in C++:
The one I will implement will have more edges and vertices, but will use this triangle style. I was wanting to create something that I could ...
8
votes
4answers
291 views
Origin of structures and classes
What design and implementation issues did programmers have to solve when they decided first to use structures and classes?
When did this happened and who were the pioneers behind these ideas?
Note, ...
3
votes
1answer
159 views
Logic required to solve a problem relating to location of objects
I have raised a question on dba.stackexchange.com but as the heart of my question is in fact to do with logic I have raised a more general representation of my issue here. I think it is the right ...
5
votes
3answers
3k views
Abstract Data Type and Data Structure [duplicate]
It's quite difficult for me to understand these terms. I searched on google and read a little on Wikipedia but I'm still not sure. I've determined so far that:
Abstract Data Type is a definition of ...
9
votes
2answers
552 views
What is the most space efficient way to implement a graph data structure?
I typically implement graphs as doubly linked lists but this is fairly space inefficient in my experience as I need k pointers/references for k neighbors so for an undirected graph I'd have ~2k ...
35
votes
8answers
2k views
How should I build the data structure for a dynamic, unlimited-size “maze”?
I'm not actually sure that "maze" is the correct term. Basically users start in a single Room that has 4 doors (N, S, E, and W). They can go in any direction, and each subsequent room is contains ...
1
vote
3answers
578 views
Programming language with pattern matching in trees
I'd like to prototype a computer algebra system. An equation would be represented by a tree and rules would be defined - similarly to mathematical axioms - by specifying a pattern (in the tree) and a ...
1
vote
4answers
446 views
data structure for file search
I've asked this question before and I got a few answers/idea but I'm not sure how to implement them.
I'm building a telecom messaging solution, currently I'm using Database to save my ...
10
votes
2answers
924 views
When programmers talk about “data structures”, what are they referring to?
When programmers talk about "data structures", are they only talking about abstract data types like lists, trees, hashes, graphs, etc.?
Or does that term include any structure that holds data, such ...
9
votes
4answers
1k views
Are trees organised by a “firstchild, nextsibling” structure? If not, why not?
Usually, tree data structures are organised in a way that each node contains pointers to all its children.
+-----------------------------------------+
| root ...
6
votes
4answers
322 views
Is there a way to track data structure dependencies from the database, through the tiers, all the way out to a web page?
When we design applications, we generally end up with the same tiered sets of data structures:
A persistent data structure that is described using DDL and implemented as RDBMS tables and columns.
A ...
5
votes
2answers
486 views
What is the Bible of Hashing?
Is there a Cormen-like reference on Hashes and Hashing? This particular structure has seen little attention in my CS education for some reason but I'd like to learn more as they seem to be everywhere. ...
3
votes
4answers
1k views
Where would I typically use a Deque in production software?
I'm fairly familiar with where to use Stacks, Queues, and Trees in software applications but I've never used a Deque (Double Ended Queue) before. Where would I typically encounter them in the wild? ...
5
votes
8answers
3k views
What is the difference between an Array and a Stack?
According to Wikipedia, a stack:
is a last in, first out (LIFO) abstract data type and linear data structure.
While an array:
is a data structure consisting of a collection of elements ...
16
votes
2answers
515 views
What is an Aguri tree?
Going through some old Hacker News items, I came across a post from a user that said
Aguri trees, which marry a bounded-size radix trie (like you'd use in a software routing table) to an LRU list, ...
13
votes
2answers
384 views
What is the canonical reference on probabilistic data structures?
I've heard of probabilistic data structures like Skip Lists and Bloom Filters being immensely useful and I'd like to learn more about them in general. Is there a canonical reference on the subject on ...
6
votes
4answers
2k views
Real world usage of DelayQueue
What would be a real world usage of DelayQueue, what common problem it was design to solve?
2
votes
1answer
456 views
Keeping binary search tree balanced
I am educating myself on algorithms and data structures. For that, I am doing a simple program that would read lines like this:
bdhj 168.24
dahf 42.88
dhfa 128.92
First column represents an account ...
2
votes
10answers
386 views
Standardized Data Structure Interface
I want to work with a variety of data structures (arrays, singly/doubly linked lists, sorted structures, etc.) on a plug-and-play basis. For example, I want to be able to easily swap in and out the ...
-3
votes
1answer
281 views
Writing-Reading a hashtable to a text file
I'm implementing a hashtable structure for a dictionary. Dictionary is in a text file. There are 2 words on each line. I'm generating the hashtable by using the first word as a key. I'm holding the ...
2
votes
2answers
232 views
How would you transfer data between your data structures and databases?
I'm learning programming in school and I have this question that's bugging me about data structures and transferring the information stored inside them to databases. We're doing just small systems - ...
16
votes
6answers
1k views
Is it a good practice to use smaller data types for variables to save memory?
When I learned the C++ language for the first time I learned that besides int, float etc, smaller or bigger versions of these data types existed within the language. For example I could call a ...
2
votes
4answers
450 views
Is it possible to efficiently store all possible phone numbers in memory?
Given the standard North American phone number format: (Area Code) Exchange - Subscriber, the set of possible numbers is about 6 billion. However, efficiently breaking down the nodes into the sections ...
0
votes
1answer
582 views
Equivalent of #map in ruby in golang
I'm playing with Go and run into something I'm unable to find in Google, although there is certainly something that exists:
I'm using the following struct:
type Syntax struct {
name string
...
0
votes
7answers
2k views
Why would you use data structures (ie Binary Trees, Linked Lists) in your jobs/side projects? [closed]
It seems to me that, for everyday use, more primitive data structures like arrays get the job done just as well as a binary tree would. My question is how common is to use these structures when ...
0
votes
1answer
117 views
Whats the difference between a Ledger and a list of transactions?
re: algorithm and data structure concepts
When accountants talk about Ledgers they have something very specific in mind. As a programmer I'm very used to thinking about tables of information, but ...
2
votes
5answers
1k views
An XML file or Database?
I am re-writing a section of my site and am trying to decide how much of a rewrite this will be. At the moment I have a web service feed that generates an xml once per day. I then use this xml file on ...
44
votes
8answers
4k views
How to represent a Rubik's Cube in a data structure
If I am attempting to simulate a Rubik's Cube, how would you create a data structure to store the cube's state in memory, with X number of tiles per side?
Things to consider:
the cube can be of any ...
1
vote
1answer
115 views
differences between Statistics::R and Statistics::useR — which one should I look into? [closed]
I've been looking into tools to seamlessly data munge from Perl into R and back into Perl, and I've seen two packages recommended: Statistics::R and Statistics::useR which seem to cater for different ...
2
votes
4answers
207 views
Is it better to use a Database or a data structure for network stack?
I've built a multi threaded messaging application in C and I'm currently using a MySQL Memory table to save the session ID, but I'm not sure whether this was a good decision or not.
It works like ...
2
votes
4answers
490 views
Data Structures usage and motivational aspects
For long student life I was always wondering why there are so many of them yet there seems to be lack of usage at all in many of them. The opinion didn't really change when I got a job.
We have ...
2
votes
1answer
122 views
What conventions or frameworks exist for MVVM in Perl?
We're using Catalyst to render lots of webforms in what will become a large application. I don't like the way all the form data is confusingly into a big hash in the Controller, before being passed to ...
8
votes
5answers
906 views
Data structures in functional programming
I'm currently playing with LISP (particularly Scheme and Clojure) and I'm wondering how typical data structures are dealt with in functional programming languages.
For example, let's say I would like ...
2
votes
3answers
313 views
What is the name of this tree?
It has a single root and each node has 0..N ordered sub-nodes . The keys represent a distinct set of paths. Two trees can only be merged if they share a common root. It needs to support, at minimum: ...
8
votes
3answers
10k views
Dictionary vs List
So I ran into a Dictionary<int, int> today at work. This just seemed weird to me because I would have probably just used a List<int> instead. Is there a difference and would there be a use ...
1
vote
2answers
416 views
In order traversal of M way Trees
If we have a 4 way tree such as the one shown below, and we do an in order traversal, what would the output of the in-order traversal be for an M-way tree?
In which order would the nodes be visited? ...
5
votes
4answers
207 views
Users creating instances from a template - is there a software pattern that corresponds to this use case?
I am looking into designing a system where users build a template item and then create many instances based on this template.They then need to be able customise each instance but I also need for them ...
8
votes
5answers
798 views
What data structure should I use for this caching strategy?
I am working on a .NET 4.0 application, that performs a rather expensive calculation on two doubles returning a double. This calculation is performed for each one of several thousand items. These ...
6
votes
4answers
235 views
Is there a pattern that will help with this data structure
I'm doing a java project. My main structure contains 2 lists with elements of type A the other type B. B itself contains a list of objects which may contain elements of A.
It must be that when an ...
