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1
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2answers
63 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
138 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
33 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 ...
3
votes
2answers
2k 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 ...
2
votes
1answer
59 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
113 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
169 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 ...
0
votes
1answer
53 views

Closest Point to Moving Target

I have a target which is constantly moving, and only its current position is ever known. I have about one hundred objects surrounding it, also only who's current positions are ever known. I am ...
3
votes
4answers
314 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 ...
0
votes
2answers
114 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
52 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
135 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
352 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 ...
1
vote
1answer
313 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
35 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
91 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
295 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 ...
0
votes
3answers
277 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 ...
1
vote
2answers
326 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
115 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 ...
26
votes
10answers
4k views

When I test out the difference in time between shifting and multiplying in C, there is no difference. Why?

I have been taught that shifting in binary is much more efficient than multiplying by 2^k. So I wanted to experiment, and I used the following code to test this out: #include <time.h> #include ...
0
votes
0answers
34 views

Are Components ideal for packaging and reusing find() requests?

I find myself loading several models over and over again throughout my application. Instead of typing the code to load the model, run a find, would it be reasonable to put that code in a method and ...
3
votes
2answers
91 views

Trivially Sortable Encoding for Arbitrary-Precision Decimals

I'm looking for a reasonably(*) space-efficient way to encode arbitrary-precision decimals (e.g. BigDecimal), such that when sorting the bit-pattern of the encodings lexicographically, the numbers ...
1
vote
1answer
35 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 ...
2
votes
5answers
297 views

Simplicity-efficiency tradeoff

The CTO called to inform me of a new project and in the process told me that my code is weird. He explained that my colleagues find it difficult to understand due to the overly complex, often new ...
1
vote
3answers
211 views

Is there a difference in resource allocation & efficiency between a web app and a compiled one? [closed]

I'm a web developer. I feel like I develop less resource-intensive functionality often times, because I have this feeling that if I ask too much of the web app (animation, calculation, connections, ...
2
votes
2answers
280 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
votes
1answer
272 views

How to code efficiently? [duplicate]

I often compare my code to others and I find their solution more efficient and shorter than mine. Although both solutions work, I can't help it but wonder if mine is not adequate enough. As a result, ...
0
votes
1answer
54 views

Replacing string comparisons with dictionary lookups

Given 2 strings s1 and s2, if I do a simple equality check , it is considered to be O(n) when calculating algorithm efficiency. So, if I am using a brute force approach for the rotated substring ...
3
votes
1answer
191 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 ...
0
votes
1answer
123 views

How to Learn Doing it Right Way? [closed]

I am self taught web developer. I do not have any computer science degree from university. I know HTML5, CSS3, Javascript, PHP and some Python. But I am having difficulties about being efficient. When ...
0
votes
3answers
409 views

Least Change Problem with Thousands of Denominations

In a hypothetical economy there are currency units that can represent thousands of different values. So, for example there might be coins worth 1c, 3c, 5c, 7c, 7.5c, 80c, 8001.5c etc. Given a list of ...
0
votes
1answer
42 views

lots of images and ajax, or better solution?

I have a control where the user can select a value for the x and y axis from 2 dropdowns, and then there is a 4 by 4 grid (an image) which will show what their selections correspond to (updating ...
0
votes
2answers
398 views

Quick algorithm to find matches between two arrays

I'm faced with the following problem: I have an array which is produced by the parsing of a yaml file which contains patterns in the following structure. "Programming books" Title: a ...
0
votes
1answer
62 views

How to prevent re-checking already-checked data?

I have a class with a validId($id) method that is called by the constructor and by public function load($id). The method queries the database to see if the id exists and returns true/false. The ...
9
votes
5answers
632 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 ...
5
votes
3answers
7k views

Quickest way to split a delimited String in Java

I am building a Comparator that provides multi-column sort capability on a delimited String. I am currently using the split method from String class as my preferred choice for splitting the raw String ...
0
votes
1answer
102 views

Are expensive operations for a user bad for other users?

Let's say user A does something expensive (regarding CPU and/or memory), which takes a few seconds. Concurrently, user B needs a very small amount of computing time. In this case, will the computing ...
1
vote
2answers
329 views

Making an algorithm more efficient

I have a question about the efficiency of an algorithm: You have a list of x,y points Now I want to get all the points that are up to 5 units away from a reference x,y point How do you calculate it ...
0
votes
1answer
120 views

Is creating a separate pool for each individual png image in the same class appropriate?

I'm still possibly a little green about object-pooling, and I want to make sure something like this is a sound design pattern before really embarking upon it. Take the following code (which uses the ...
1
vote
3answers
881 views

Storing a value vs calling reference for repeated use in Java

I have an old habit of avoiding calling references multiple times, both for easier to read/maintain code, and for possible efficiency. But I'm wondering which is more efficient (memory, performance, ...
4
votes
2answers
602 views

How much logic can be put into an object-pooling factory class before it does more harm than good?

The main language I'm interested in doing object pooling in is AS3, which is known to need it in many cases. In the past I've always made a brand new factory class for every type I was going to try ...
6
votes
5answers
418 views

Maintaining good form while learning new technologies

I find that I have to learn new technologies fairly regularly as a contractor in order to keep competitive. However, I also find that (not only, but especially) in these circumstances, I tend to end ...
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 ...
2
votes
2answers
414 views

When is a code considered tight and how does it increase efficiency of the code?

I have read many times that insertion sort has tight code and hence the hidden constant factor in its asymptotic complexity is smaller. I just read yesterday that quick sort has tight code just like ...
5
votes
4answers
598 views

How do you keep track of what stage you are at in a program? [closed]

Like many, I'm developing a couple of applications on my own (not at the same time) to eventually sell. But I also have websites to run, college work and a social life etc., so often I can forgot what ...
17
votes
7answers
2k views

Does modular programming affect computation time?

Everyone says that I should make my code modular, but isn't it less efficient if I use more method calls rather than fewer, but larger, methods? What is the difference in Java, C, or C++ for that ...
3
votes
1answer
203 views

Processing every leaf under a node in a tree efficiently

Short version: In a tree (non-binary) with many levels of children, where each node can have multiple leaves, what is the best way to tally leaves that meet a certain condition given a node? Long, ...
9
votes
7answers
6k 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 ...
1
vote
1answer
346 views

Can web apps allow fast data-typists to “type-ahead”?

In some data entry contexts, I've seen data typists, type really fast and know so well the app they use, and have a mechanic quality in their work so that they can "type ahead", ie continue typing and ...