Questions regarding efficient storing and representing data within a software application.

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2
votes
3answers
982 views

What data structure could a word processor use to map the user's caret position/text selection to its internal representation of the document?

Word processors (e.g. Microsoft Word) display documents to the user as styled text. The user can select a part of this text and apply styles to it, and edit the text. The word processor must (I ...
3
votes
1answer
123 views

Representing domain objects

This is related to my recent question regarding naming awkward domain objects. A number of answers indicated I was using the wrong representation for the domain objects. To summarize, I chose to use ...
0
votes
1answer
907 views

Simple dependency tree diagram generator [closed]

I have a need to produce a simple dependency tree diagram. The input data would be in the following simple format: ITEM_NAME DEPENDENCY ---------------------------- ITEM_101 ITEM_75 ITEM_102 ...
3
votes
2answers
3k views

How, when, and why do developers use custom data structures in python?

Python's lack of pointers makes data-structure construction intuitively more challenging, and has so much built in functionality that, as an amateur, I can't see when, why, or how you would create ...
20
votes
3answers
782 views

How do I express subtle relationships in my data?

"A" is related to "B" and "C". How do I show that "B" and "C" might, by this context, be related as well? Example: Here are a few headlines about a recent Broadway play: David Mamet's Glengarry ...
4
votes
3answers
929 views

Is it conceivable to have millions of lists of data in memory in Python?

I have over the last 30 days been developing a Python application that utilizes a MySQL database of information (specifically about Norwegian addresses) to perform address validation and correction. ...
9
votes
5answers
2k 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 ...
4
votes
2answers
1k views

Which design better when use foreign key instead of a string to store a list of id

I'm building online examination system. I have designed to table, Question and GeneralExam. The table GeneralExam contains info about the exam like name, description, duration,... Now I would like to ...
4
votes
2answers
500 views

Fast set indexing data structure for superset retrieval

I am given a set of sets: {{a,b}, {a,b,c}, {a,c}, {a,c,f}} I would like to have a data structure to index those sets such that the following "lookup" is executed fast: find all supersets of a given ...
15
votes
4answers
1k views

What did Bill Gosper mean by saying a data structure is just a stupid programming language?

There's a quotation by Ralph William Gosper, Jr that says: A data structure is just a stupid programming language. What did he mean by this? Alas, all I can find in Google about it is ...
5
votes
2answers
1k views

Data structure for pattern matching

Let's say you have an input file with many entries like these: date, ticker, open, high, low, close, <and some other values> And you want to execute a pattern matching routine on the ...
0
votes
3answers
198 views

I need some help creating a non-binary tree (or some other data structure that will better solve my problem)

I have about ten lists of numbers and some strings. Each list has about <= 30K lines. Each line on a list has a distinct number. I need to build an efficient way of finding all the lines in each ...
16
votes
6answers
4k 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
2answers
8k views

Generic Adjacency List Graph implementation

I am trying to come up with a decent Adjacency List graph implementation so I can start tooling around with all kinds of graph problems and algorithms like traveling salesman and other problems... ...
6
votes
1answer
295 views

How to design data structures for sharding?

When designing data structures for an application, what are some best practices to make sure it can be sharded? In particular, which of the following is better: Creating relationships in databases ...
6
votes
1answer
2k views

What is the usage of Splay Trees in the real world?

I decided to learn about balanced search trees, so I picked 2-3-4 and splay trees. What are the examples of splay trees usage in the real world? In this Cornell: ...
3
votes
1answer
1k views

How should I architect my Model and Data Access layer objects in my website?

I've been tasked with designing Data layer for a website at work, and I am very interested in architecture of code for the best flexibility, maintainability and readability. I am generally acutely ...
1
vote
2answers
734 views

Count function on tree structure (non-binary)

I am implementing a tree Data structure in c# based (largely on Dan Vanderboom's Generic implementation). I am now considering approach on handling a Count property which Dan does not implement. The ...
5
votes
2answers
289 views

Data structures for storing finger/stylus movements in drawing application?

I have a general question about creating a drawing application, the language could be C++ or ObjectiveC with OpenGL. I would like to hear what are the best methods and practices for storing strokes ...
2
votes
1answer
345 views

2D grid with multiple types of objects

This is my first post here in programmers.stackexchange (I'm a regular on SO). I hope this isn't too general. I'm trying a simple project to learn Java from something I've seen done in the past. ...
3
votes
3answers
576 views

Internal Mutation of Persistent Data Structures

To clarify, when I mean use the terms persistent and immutable on a data structure, I mean that: The state of the data structure remains unchanged for its lifetime. It always holds the same data, ...
6
votes
1answer
166 views

Unit testing a text index

Consider a text index such as a suffix tree or a suffix array supporting Count queries (number of occurrences of a pattern) and Locate queries (the positions of all the occurrences of a pattern) over ...
4
votes
1answer
508 views

Amazon Kindle - Whispersync implementation?

For those who are not aware of Kindle's whispersync, here is how it works (from amazon.com): "...Whispersync synchronizes the bookmarks and furthest page read among devices registered to the same ...
2
votes
1answer
5k views

Most efficient Implementation a Tree in C++

I need to write a tree where each element may have any number of child elements, and because of this each branch of the tree may have any length. The tree is only going to receive elements at first ...
0
votes
1answer
57 views

Create association between informations

I deployed a project some days ago that allow to extract some medical articles using the results of a questionnaire completed by a user. For instance, if I reply on questionnaire I'm affected by ...
1
vote
2answers
1k views

Does the Head(start) pointer of Doubly Linked list points previously to the tail(last) node

I have one question in my mind that in case of circular doubly linked list the head pointer of the doubly linked list also logically point to the next pointer of the tail node of the linked list and ...
3
votes
3answers
604 views

Data structure: sort and search effectively

I need to have a data structure with say 4 keys . I can sort on any of these keys. What data structure can I opt for? Sorting time should be very little. I thought of a tree, but it will be only help ...
9
votes
4answers
2k views

Analyzing Memory Usage: Java vs C++ Negligible?

How does the memory usage of an integer object written in Java compare\contrast with the memory usage of a integer object written in C++? Is the difference negligible? No difference? A big difference? ...
1
vote
2answers
1k views

What are the most known arbitrary precision arithmetic implementation approaches?

I'm going to write a class library for .NET which provide an implementation of arbitrary precision arithmetic for integer, rational and maybe complex numbers. What best known approaches should I ...
17
votes
5answers
6k views

Configuration data: single-row table vs. name-value-pair table

Let's say you write an application that can be configured by the user. For storing this "configuration data" into a database, two patterns are commonly used. The single-row table CompanyName | ...
0
votes
5answers
1k views

Learning basic algorithms - better C or C++? [closed]

I'm studying fundamental algorithms (quicksort, mergesort, binary trees, etc..) and I'm going to re-code every algorithm by scratch to learn how they work. Should I code them in C or C++? I think with ...
6
votes
4answers
448 views

Understanding the Macro Aspects of Data Structures

I am studying data structures right now, but I still need to find a teacher/site/book with a clear explanation of the macro aspects of this topic. What I mean is: most lessons/text books mix ...
1
vote
3answers
270 views

I want to create an open data format… but I don't really know what that is

I have found a need for a standardization for storage and recording of data relating to diabetes information (I don't think there's any, but I may have missed it). To that end I made this github ...
11
votes
3answers
4k views

AVL Trees and the REAL world

in school we are taught how we can balance an AVL tree upon an insertion or deleting. How is this type of knowledge actually going to be useful in the real world? Can someone give an example on when ...
0
votes
1answer
185 views

Converting data-structure in Perl [closed]

A function produces this hash of arrays: 'KEYNAME1' => ARRAY(0x1edeeb0) 0 'val11' 1 'val12' 2 'val13' 'KEYNAME2' => ARRAY(0x1efacb8) 0 'val21' 1 'val22' 2 'val23' ...
7
votes
5answers
2k views

What do you call classes without methods?

What do you call classes without methods? For example, class A { public string something; public int a; } Above is a class without any methods. Does this type of class have a special name?
1
vote
1answer
262 views

hash with file instead of array

Is it possible to use hash function but with File instead of Array, and it's gonna be saving the record in a file position and then search will fseek to that position, but I'm not sure how to open a ...
0
votes
7answers
4k 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 ...
3
votes
8answers
1k views

Strategy/algorithm to divide pot to chips

I want to split poker pot to chips. Example: Pot = $17.500. I have the endless piles of chips. I have the following types of chips: ChipsTypes = [$1, $5, $10, $25, $100, $500, $1.000, $5.000, ...
4
votes
4answers
553 views

Appropriate data structure for deeply nested data?

I can't figure out what would be an appropriate data structure for my problem. I need to write a script that will count some events. Input is a list of events (thousands of them). Each event is an ...
7
votes
1answer
5k 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. ...
104
votes
24answers
56k views

Why are data structures so important in interviews?

I am a newbie into the corporate world recently graduated in computers. I am a java/groovy developer. I am a quick learner and I can learn new frameworks, APIs or even programming languages within ...
1
vote
2answers
116 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
1k 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. ...
7
votes
3answers
734 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, ...
6
votes
4answers
473 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 ...
1
vote
1answer
381 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 ...
7
votes
4answers
881 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 ...
2
votes
1answer
217 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 ...
2
votes
4answers
1k 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 ...