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

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2
votes
1answer
305 views

What is the “best practice” for converting an external API's data structure?

When an API's data structure does not fit well with an angular app, I am trying to determine the best-practice in my specific design and implementation for converting it to a usable structure. I was ...
2
votes
1answer
173 views

Tokenizing Text Held in a Rope Data Structure

I am building a text editor which makes use of a Ragel based tokenizer to support syntax highlighting. I am considering the use of a rope data structure to support efficient modifications and ...
5
votes
3answers
2k views

How exactly is an Abstract Syntax Tree created?

I think I understand the goal of an AST, and I've built a couple of tree structures before, but never an AST. I'm mostly confused because the nodes are text and not number, so I can't think of a nice ...
0
votes
1answer
103 views

How to make the members of my Data Access Layer object aware of their siblings

My team currently has a project with a data access object composed like so: public abstract class DataProvider { public CustomerRepository CustomerRepo { get; private set; } public ...
3
votes
2answers
179 views

Should I use nested matrices or dictionaries?

As per Should I ask my question about which data structure to use here? I'm asking this here. Hopefully this isn't too implementation specific. I'm currently developing a program that will represent ...
10
votes
2answers
662 views

How to represent a graph with multiple edges allowed between nodes and edges that can selectively disappear

I'm trying to figure out what sort of data structure to use for modeling some hypothetical, idealized network usage. In my scenario, a number of users who are hostile to each other are all trying to ...
3
votes
2answers
75 views

1 class model or 3 class models? 1 for each - UI, Hardware API Library, and Database

I've always used one class model in all 3 area's of my projects. User Interface, Hardware API (for data collection), Database (entity database context). Every new project only seems to grow in size, ...
2
votes
1answer
191 views

How to store satellite data in C data structutres

I've been reading through Introduction To Algorithms 3rd Ed, and am really enjoying the material; however, I am having difficulty in implementing some practical situations. It's not the theory, or ...
0
votes
1answer
65 views

How to chain together points in an array

I have a series of points with lengths and rotations like this: I need to create separate chains from points whose lines overlap but I’m having real trouble doing this efficiently. I have an array ...
0
votes
3answers
223 views

Why is the complexity of fetching a value from an array be O(1)?

How come the complexity of fetching a value from an array by it's index is O(1)? I thought the algorithm has to go through all the indexes, find the correct index, and then know what value to return. ...
4
votes
2answers
305 views

Are bloom filters actually faster than hashes, even taking in account cache?

Bloom filters look really great when you consider you can determine if an Int is in a set with 99% certainty in constant time. But so can hashes, with the only difference that, in a hash, most of the ...
0
votes
2answers
238 views

boolean operations in C using bitfields

I am trying to implement boolean data type in C. Basically, I am working with sets. The following code can be used to access each bit but I am unsure whether I can represent sets using this method. ...
2
votes
1answer
135 views

How should data transfer between a client and a web API for normalized data be designed?

I want to design an API backed by some database (doesn't really matter which, but to make the discussion more interesting, let's say it's Mongo - explanation below) which sends data to a client. The ...
5
votes
2answers
346 views

Is it safe in Haskell to save a data structure to a file using “show”, and retrieve it using “read”?

Say I have the following types: type EndsTup = (Int,Int) -- (0-based index from start or end, Frequency) type FreqTup = (Char, [EndsTup], [EndsTup]) -- (Character, Freqs from start, Freqs ...
0
votes
3answers
2k views

Nested maps vs. combined keys

in the project I am currently working on we had three different types of prices depending on the age of the user (adult, child, etc...). So we had on the DB a table looking like this: PRICES type ...
3
votes
2answers
252 views

How can a true Vector be implemented in Haskell?

How could a true Vector type be implemented in Haskell? In order for something to be a Vector, it has to be stored sequentially in memory, with O(1) random access. But Haskell hides its memory ...
7
votes
1answer
199 views

Are “skip deltas” unique to svn?

The good folks who created the SVN version control system use a structure they refer to as "skip deltas" to store the revision history of files internally. A revision is stored as a delta against an ...
4
votes
3answers
2k views

Data Oriented Design - impractical with more than 1-2 structure “members”?

The usual example of Data Oriented Design is with the Ball structure: struct Ball { float Radius; float XYZ[3]; }; and then they make some algorithm that iterates a std::vector<Ball> ...
3
votes
1answer
374 views

Is using MultiMaps code smell? If so what alternative data structures fit my needs?

I'm trying to model nWoD characters for a roleplaying game in a character builder program. The crux is I want to support saving too and loading from yaml documents. One aspect of the character's is ...
2
votes
2answers
482 views

Best way of storing a small number of user credentials

I'm working on a messaging application, based on a server/client architecture. Now I am thinking about the way how to store the user credentials. It's not a huge number, just about 20 entries with ...
3
votes
3answers
242 views

Quadtree with duplicates

I'm implementing a quadtree. For those who don't know this data strucutre, I am including the following small description: A Quadtree is a data structure and is in the Euclidean plane what an ...
2
votes
2answers
365 views

How to present a stable data model in a public API that allows internal data structures to be changed without breaking the public view of the data?

I am in the process of developing an application that allows users to write C# scripts. These scripts allow users to call selected methods and to access and manipulate data in a document. This works ...
1
vote
3answers
438 views

Tournament bracket method to put distance between teammates

I am using a proper binary tree to simulate a tournament bracket. It's preferred any competitors in the bracket that are teammates don't meet each other until the later rounds. What is an efficient ...
0
votes
2answers
203 views

High-level strategy for distinguishing a regular string from invalid JSON (ie. JSON-like string detection)

Disclaimer On Absence of Code: I have no code to post because I haven't started writing; was looking for more theoretical guidance as I doubt I'll have trouble coding it but am pretty befuddled on ...
3
votes
2answers
502 views

Data structure for grid with negative indeces

Sorry if this is an insultingly obvious concept, but it's something I haven't done before and I've been unable to find any material discussing the best way to approach it. I'm wondering what's the ...
2
votes
1answer
339 views

Where to implement thread-safety logic for my queue data structure?

I will immediately confess that I do very little multithreading, so questions of style and organization in this domain a little fresh to me. I've written a data structure (in Python, if that matters) ...
0
votes
2answers
627 views

Exercise 3.6: Skiena Algorithm Design Manual

I am preparing for interview and try to solve the exercise problems of the book. 3-6. [5] Describe how to modify any balanced tree data structure such that search, insert, delete, minimum, and ...
2
votes
2answers
401 views

Most efficient way to store this collection of moduli and remainders?

I have a huge collection of different moduli and associated with each modulus a fairly large list of remainders. I want to store these values so that I can efficiently determine whether an integer is ...
1
vote
1answer
40 views

Benefits of caching the count of items in a data structure versus on-demand calculation?

Given a data structure, I want to provide an API method Size which returns the number of items. I am vacillating between 2 approaches: Maintain a count and increment/decrement it in response to ...
12
votes
2answers
2k views

What is the relationship between data structures and algorithms? [closed]

I have been searching for a good online course in data structures but have found that Google also returns results for algorithms courses, which say stuff like: In this course you will learn ...
5
votes
2answers
671 views

Overriding GetHashCode in a mutable struct - What NOT to do?

I am using the XNA Framework to make a learning project. It has a Point struct which exposes an X and Y value; for the purpose of optimization, it breaks the rules for proper struct design, since its ...
-2
votes
1answer
375 views

Does implementing algorithms improve your programming skills? [duplicate]

I have been self studying algorithms and data structures for some time now and currently enjoying it. Whenever I understand an algorithm, I usually try to code them from scratch for fun and I always ...
1
vote
2answers
296 views

Traversing an AST using Visitors

I'm writing a compiler for a C-like language, and I'm looking for an elegant way to traverse my abstract syntax tree. I'm trying to implement the Visitor pattern, although I'm not convinced that I'm ...
3
votes
6answers
2k views

How did programmers implement Linked list ideas before the object oriented paradigm?

Linked lists, as far as I have seen, are largely implemented using object-oriented ideas. (having an object that holds some information and the address of the next link). How were Linked-lists ...
1
vote
3answers
333 views

what is the javascript internal data structure?

Consider a basic js object: var obj={x:1,y:'2'}; Is this stored internally as a hashtable or does js use a different mechanism for key value pairs? If they are hash tables does anyone know how they ...
0
votes
1answer
759 views

What happens to equal elements when inserting into a binary search tree?

Most BST examples show a sample of a BST with unique values; mainly to demonstrate the order of values. e.g. values in the left subtree are smaller than the root, and values in the right subtree are ...
2
votes
5answers
540 views

how to design a stack without using java library or using list [closed]

I have a question how to design a stack without using list or array? This is one question that I want to think about as I want to better understand stack.
0
votes
1answer
2k views

Is a PHP array an example of a dynamic data structure?

I did my homework, and it says that dynamic data structures are "data structures that change in size as a program needs it to by allocating and de-allocating memory from the heap". So I was ...
5
votes
2answers
2k views

Why does Python use hash table to implement dict, but not Red-Black Tree? [closed]

Why does Python use hash table to implement dict, but not Red-Black Tree? What is the key? Performance?
2
votes
2answers
408 views

Collection vs data structure vs aggregate

I know three terms that have to do with storing objects or data. I'm not sure I understand the exact differences between the terms. Please confirm if what I'm about to write is accurate. A data ...
0
votes
1answer
175 views

What is a good way to store geographical data for distance calculations

What would be the best way to store data in a database for geographical calculations? Say I have an ItemsForSale table paired to a Users table which holds their geo location. I know I can use latitude ...
-2
votes
1answer
77 views

How to maintain trade off between number of columns in table vs join operations? [closed]

I have learnt that if there are more columns in table, then get those results using join query. How to decide the max number of columns in table? How feasible is "Join Operation" if too many table ...
1
vote
2answers
749 views

What is the underlying mechanism behind va_list and where is it defined?

http://www.cplusplus.com/reference/cstdarg/va_list/ According to the above link, va_list is an argument or parameter used in some macros - va_start, va_arg, va_end. These macros are present in the ...
0
votes
2answers
548 views

Data structures VS Classes and what happens if they merge? [closed]

Alright so I've learned this: Classes have public methods that perform operations on the class's data and they hide away their implementations. Data structures on the other hand, completely expose ...
0
votes
2answers
319 views

Most efficient data structure for implementing inheritance structure without classes

I have a number of types that all relate to each other in terms of them being 'derived' from one another. I'd need a way to do is relationships, which made me initially think of classes, but I ...
0
votes
1answer
65 views

Testing the Consumers of Subclassed Data Structures

PHP's SplQueue does not include a clear() or reset() function to wipe data out of the data structure. My application requires that functionality. This leaves two options: A) Create a subclass of ...
3
votes
4answers
406 views

fast n-gram access data structure

TL;DR Is there a data structure that'd quickly let me match words at any point (e.g., 'foo' matches 'foobar' and 'zoofoo'), and, ideally, returns a list of "characters that show up after the needle" ...
1
vote
1answer
231 views

Chained ruleset parsing and evaluation code: recommendations?

So I have to write a filtering system, which may apply preprocessed ruleset to data - and trigger some actions defined in the ruleset while continuing its evaluation. <ruleset name="1"> ...
0
votes
1answer
92 views

What is the difference between a Splay Tree and an Optimal Binary Search Tree?

Both these trees try to keep the most frequently accessed element at the top. Is there any difference between these two trees?
1
vote
2answers
176 views

Minimize touching the already-working code when a radical change is required

I have a code that highly relies on an Array structure like the following: $array['customer'][$customer_id]['details'][..]; // it goes to about 10 levels deep However, after almost two years ...