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1
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2answers
79 views

Multi-pattern matching

I have a given byte array in C and I need to match it against several byte arrays and return true if there is any match. I can make various memcmp's but I feel that it is very inefficient. Do you ...
0
votes
2answers
74 views

Are case-studies an effective way of getting efficiency-focused team members to be willing to trade some efficiency for quality? [closed]

Firstly, this does not suggest that efficiency and quality are in conflict... only that some methods prioritize them differently. Secondly, this is not a question of whether you agree with Scrum ...
4
votes
4answers
450 views

Why are return values from compare functions in many languages defined loosely?

Many languages define that compare functions should return ANY negative value, zero, or ANY positive value. Is there some reason that it shouldn't be clearly defined as -1 0 and 1? Does a wide range ...
3
votes
2answers
46 views

Reducing a sequence of array modification operations (insert, sort, replace, remove)

Given a plain array of values, e.g. ["Apple", "Orange", "Banana", "Strawberry"] and a list of operations from the set of [insert, delete, sort and replace], e.g. [ {cmd: "insert", index: 2, ...
1
vote
1answer
70 views

What is a good metric for guiding a switch from a prototyping language to a production language? [duplicate]

By "prototyping language", I mean one which was chosen by virtue of it's relative ease of quickly accomplishing the sort of design changes common to prototyping in a particular context. (such as data ...
1
vote
0answers
40 views

Storing/caching SQL query

If I have a very long-winded SQL query (that has multiple subqueries), but the result of which is unlikely to change from hour to hour (or even day-to-day, or possibly even week-to-week) is there some ...
2
votes
2answers
187 views

How do I make this functional DSL written in an imperative language more efficient?

Suppose I create a simple functional Domain-specific language (DSL) using an imperative language, in this case C++. Here is a simple implementation of a DSL that can has the notion of a simple value ...
4
votes
2answers
396 views

How to measure time lost due to environment problems?

I'm trying to determine how we can measure how much time the developers are loosing to poorly managed environment and inefficient ways-of-working. The goals are: Show managment how big the problem ...
0
votes
1answer
30 views

Optimizing and caching frequently accessed but rarely updated Tables

My app has some tables that will be rarely updated, probably just once in the beginning and at the system setup. Despite that, they will be frequently accessed. Almost every operation depends on ...
3
votes
2answers
293 views

How to avoid calling String.Replace() in a loop?

I am building a very simple email templating system in C#, and it works amazingly, but I have a personal issue with the way I designed it: Template looks like this: Hello {UserName}, Welcome to ...
3
votes
2answers
6k views

Which way is more efficient for getting the space count?

I have just started reading Cracking the Coding Interview. One of the problems (specifically 1.4) after solving and then looking at the answer made me question the way it is done and decided to post ...
1
vote
1answer
57 views

Need semi-efficient algorithm for 3-dimensional increasing sequence

I have a set of puzzle challenges for a prototype jigsaw puzzle kit, similar to commercial products offered by Thinkfun and Popular Playthings. I have a candidate list of 300 puzzle challenges and ...
2
votes
1answer
110 views

Closest Point to Moving Target

I have a target which is constantly moving, and only its current position is ever known. I also have about one hundred objects surrounding it, and for each of these only the current position is ...
15
votes
3answers
10k views

Is there any reason to use varchar over text columns in a database?

Is varchar just a remnant from before text came around, or are there use cases where you would want to use a varchar? (Or char for that matter..) (I use Postgres and MySQL (MyISAM) daily, so those ...
0
votes
0answers
39 views

Handling image and audio files in iOS

Currently I have an iOS app that downloads image and audio files from a server, but each view controller downloads its own set of image and audio files (This is because each view controller needs a ...
10
votes
5answers
695 views

Can a pure-functional solution to this problem be as clean as the imperative?

I have an exercise in Python as follows: a polynomial is given as a tuple of coefficients such that the powers are determined by the indexes, e.g.: (9,7,5) means 9 + 7*x + 5*x^2 write a function to ...
4
votes
1answer
270 views

How does modulus work?

I am not asking asking how the mathematical concept of modulus works, or how 20 % 3 == 2 I understand this fine. I'm more curious how the compiler/interpreter determines this. I can think of a very ...
17
votes
5answers
9k views

How to slow down your computer (for testing purposes)?

As most people agree, encouraging developers to make fast code by giving them slow machines is not a good idea. But there's a point in that question. My dev machine is fast, and so I occasionally ...
8
votes
5answers
3k views

What is a good measure of testing/tester efficiency?

I am about to participate in a discussion with management regarding measuring our testing efficiency as a QA organization. The main reason behind this is that half of our team is contracted out and ...
0
votes
0answers
57 views

Single import in a large file vs. multiple imports in smaller files. [Golang]

I'm sure the folks at Google worked long and hard to ensure the programmer wouldn't have to worry about details like this, but I'm curious. In Go if I have multiple files in the same package, but ...
0
votes
5answers
540 views

Fastest way to determine if a value is in a list?

I'm aware there may not be a good solution to this problem. I'm looking for a fast algorithm that determines whether or not a value (let's say an integer) exists in a set of values, however I need the ...
14
votes
6answers
1k views

Importance of learning to google efficiently for a programmer? [closed]

This is not a debate on usage of Google being good or bad for programmers. Kindly refrain from doing so in your answers. Most people (a vast majority of who use the Internet) use Google these days. ...
2
votes
0answers
35 views

IRLBot Paper DRUM Implementation - Why keep key, value and auxiliary buckets seperate?

Repost from here as I think it may be more suited to this exchange. I'm trying to implement DRUM (Disk Repository with Update Management) as per the IRLBot paper (relevant pages start at 4) but as ...
3
votes
2answers
275 views

How can I approach creating an efficient algorithm for maximizing value with these specific constraints?

I'm having trouble coming up with an approach that isn't n^2 for this problem. Here's a contrived, simplified version I've come up with: Let's say you're a company that needs 4 employees to launch in ...
1
vote
1answer
278 views

How would a compiler turn an else-if cascade into a switch?

I don't like switch in C and its descendants. Maybe it's the need for a break or the clumsiness of the syntax requiring a shifting of mental gears, I don't know. Whatever the reason, I will almost ...
1
vote
2answers
87 views

What is better for scalability for this specific dataset, MongoDB or MySQL?

I have a web app which has users, forms, and volunteers signed up on those forms. Currently I am using MongoDB and have it setup with a collection for admins, and a collection for forms with ...
0
votes
1answer
219 views

Most efficient LINQ result for Contains() query

I currently use the following: var result = list.Union(otherList).SelectMany(l => l.children).ToList() foreach(var child in lotsOfChildren){ something = result.Contains(child) } I only use ...
2
votes
1answer
39 views

Comparing path strings against list of rules

I am trying to find a way to enhance a filtering algorithm. I am developing a backup software that enables users to specify custom filters to exclude unwanted files/directories. Currently when trying ...
2
votes
1answer
65 views

timed events to modulation of real-time audio

I am new very to audio programming and am having trouble figuring out the right kind of algorithm for converting control events (e.g. like MIDI) to real-time sound genesis with a buffer. At the ...
0
votes
1answer
265 views

Efficient way to map changes in a filesystem hierarchy

I'm currently working on a project that will enable file searching based on metadata found in the file. It'll be comprised of 2 parts: a filesystem crawler that passively scans for changes and ...
1
vote
2answers
292 views

What benefit is there to using recursive binary search over iterative binary search or vice versa?

In a recent assignment for my programming 2 class we tested the efficiency of searches by populating a java ArrayList with 13,040 strings. The sequential search was obviously slower than the binary ...
23
votes
4answers
30k views

Is Python Interpreted or Compiled?

This is just a wondering I had while reading about interpreted and compiled languages. Ruby is no doubt an interpreted language, since source code is compiled by an interpreter at the point of ...
9
votes
7answers
8k views

Why is binary search,which needs sorted data, considered better than linear search?

I have always heard that linear search is a naive approach and binary search is better than it in performance due to better asymptotic complexity. But I never understood why is it better than linear ...
0
votes
2answers
126 views

When trying to find out if a number is even or odd: AND 1 or OR 0

I recently learned of the trick for finding out if a binary number is odd or even. If the last bit in the number is 0, then the number is even. If it ends in a 1, then the number is odd. In the ...
3
votes
1answer
57 views

Bottleneck performance in ECS

I've been looking into building an entity-component-system. Basically, an entity is just an id wrapped around a struct, components are data belonging to that entity(and reference said id), and systems ...
4
votes
1answer
303 views

(jQuery) What is wrong with methods such as .append?

tl;dr: What is wrong with the efficiency of methods such as .append() and what can be alternatives to this? Explanation: Hello everyone. I occasionally have to build A/B tests for websites, which ...
2
votes
2answers
1k views

How does Yahoo's Smush.It work and why doesn't everyone use it?

I've recently come across an application by Yahoo called SmushIt. Apparently it does lossless compression on images. Sometimes the image size is reduced by as much as 90%. This of course has major ...
9
votes
5answers
3k views

Is try-finally expensive

In case of code where you have to do a resource cleanup before exiting a function, is there a major performance difference between these 2 ways of doing it. Cleaning the resource before every return ...
1
vote
1answer
596 views

Efficiency of C# dictionaries

C# dictionaries are a simple way to find if something exists etc etc. I have a question though on how they work. Let's say instead of a dictionary I use an ArrayList. Instead of using ContainsKey (or ...
1
vote
1answer
57 views

Should I do a different SQL table for user privacy settings or just keep it at the users table?

So I am developing a Web Application and I have some concerns about the database. I use a lot of boolean settings at the user table with the form privacy_allow_1, privacy_allow_that, ...
4
votes
1answer
129 views

How do I efficiently send notifications for different events to different users based on their preferences?

I'm creating a notification system for particular events. A user can set the criteria that match particular events (ie. New item, changed item, closed item etc) Items have different characteristics ...
0
votes
3answers
508 views

Using action array vs Switch Case [closed]

I have an occasion of code in which I will draw a different set of buttons in a screen (depending on the number of the buttons). One thought (and my current implementation) is to use an action array ...
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

Custom Domain or Attribute Reference Table or Both?

I'm designing my first real database and I'm weighing the pros and cons of how to enforce uniformity in my data. My first option is to create a custom domain and program my UI to only allow certain ...
7
votes
3answers
379 views

Computed Values and Simple Reads - A nagging pain for my Domain Driven Designs!

The problem I continually face is how to deal with computed values driven by domain logic while still working efficiently against the data store. Example: I'm returning a list of Products from my ...
5
votes
2answers
3k views

Amortized Analysis? (Worst-case Performance Guarantees)

What is Amortized Analysis? And how can it help me achieve worst-case performance guarantees in my programs? I was reading that the following techniques can help the programmer achieve Worst-case ...
0
votes
3answers
468 views

What is more efficient, a single square root or multiple divisions?

Say I make a program that calculates all possible (integral) factors of a certain number that has been input. Is it theoretically more efficient to check with all integers up to the square root of ...
8
votes
8answers
12k views

What is the best way to INSERT a large dataset into a MySQL database (or any database in general)

As part of a PHP project, I have to insert a row into a MySQL database. I'm obviously used to doing this, but this required inserting into 90 columns in one query. The resulting query looks horrible ...
1
vote
2answers
333 views

How to approach program design with respect to data strucutres and algorimths - is there an equivelant of the OO design process for d.s.'s + algs? [closed]

My applogies for probably the worst written body of text I have produced in my life and many thanks to those willing to plough through it all. I was (and still am) not able to clearly express what I ...
0
votes
2answers
125 views

Should you avoid adding unecessary stack frames?

I have been working with laravel (PHP) recently, and there is an option when using their fluent ORM to define where clauses using closures. This gives us two, functionally equivalent, ways to specify ...