In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning.

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Improve address lookup usability and accuracy?

In my application,I have a feature like this: The user wants to add a new address to the database. Before adding the address, he needs to perform a search(using input parameters like ...
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4answers
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Database fuzzy search concept

I thought about this, and have been trying to come up with solutions on how to fuzzy search a database, if for say example a user types a spelling mistake. Any glaring problems with the logic behind ...
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9answers
10k views

Is it essential to learn algorithms to be a real programmer? [closed]

I'm a PHP programmer, and until now I have not needed to learn algorithms... Now I'm start learning Python (a real programming language), because I need to use matplotlib. Does it make sense to start ...
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7answers
8k views

How important is studying algorithms and theory is to becoming a great programmer? [duplicate]

Possible Duplicate: Should I keep investing into data structures and algorithms? I'm a CS student. I want to become a really great programmer, what do I need to do to be come a great ...
10
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4answers
2k views

Interview question ranking FizzBuzz (1), implementing malloc (10) [closed]

I'd like to have your opinion on the difficulty of the following interview question: Find the contiguous subarray with maximum sum in an array of integers in O(n) time. This trivial sounding problem ...
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9answers
3k views

Card deck and sparse matrix interview questions [closed]

I just had a technical phone screen w/ a start-up. Here's the technical questions I was asked ... and my answers. What do think of these answers? Feel free to post better answers :-) Question 1: ...
0
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3answers
701 views

Fast lookup for organization hierarchy

I need a way to implement a fast lookup algorithm / system to find users very quickly in a multi-level department and multi-level employee/manager relation organization structure. Departments can ...
24
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7answers
5k views

Should I keep investing into data structures and algorithms? [closed]

These days, I'm investing heavily in data structures and algorithms and trying to solve some programming puzzles. I'm trying to code and solve with Java and Clojure. Am I wasting my time? should I ...
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5answers
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Conways Game of Life C#

Not sure if this is the correct place for this question or SO - mods please move if necessary. I am going to have a go at creating GoL over the weekend as a little test project : ...
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13answers
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Why is it better for a programmer to design the algorithm before starting to write the code?

Does an appropriate algorithm really help improve the quality and ultimately the efficiency of a program? Can we still produce a good quality program without the algorithm? Is an appropriate ...
1
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4answers
211 views

I need a public cryptography system that works on small keys [closed]

I just need it to support signing and signature verification. I need it to have public and private keys that fit each in 16 bytes. The signature itself must fit 16 bytes. I don't really care about ...
838
votes
10answers
306k views

Which hashing algorithm is best for uniqueness and speed?

Which hashing algorithm is best for uniqueness and speed? Example (good) uses include hash dictionaries. I know there are things like SHA-256 and such, but these algorithms are designed to be ...
34
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11answers
5k views

Random number generation algorithm for human brains? [closed]

Are you aware of, or have you devised, any practical, simple-to-learn "in-head" algorithms that let humans generate (somewhat "true") random numbers? By "in-head" I mean.. preferably without any ...
3
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6answers
3k views

how to prove the complexity of an algorithm mathematically

I know the fundamental algorithms and it's complexities. for e.g if Binary Search has Complexity O(log n), then how I can mathematically prove this?
4
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4answers
1k views

Building general programming skills? [closed]

I currently am quite new to programming, I've had exposure to a few languages (C#, PHP, JavaScript, VB, and some others) and I'm quite new to OOP. I was just wondering what is the best way to build ...
3
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3answers
256 views

How to query a very long list of properties fast

I have a structure for storing item properties on SQL Server: ItemId PropertyId Value 1 1 a 1 2 b 2 1 a 2 2 5 Currently there are over 130000 ...
8
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3answers
422 views

What's the best way to do a Proof of Concept shootout?

In preparation for a new release of software our company maintains, I've been working on what I believe to be a really good approach to solving our scalability issues. I have every intention of ...
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3answers
204 views

How do I handle two algorithms that seem the same but different?

I have two algorithms that share a lot of commonalities. One performs an iterative procedure, the other does just the first iteration. The results are, of course, different (one class provides results ...
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2answers
16k views

How would you implement Google Search? [closed]

Supposed you were asked in an interview "How would you implement Google Search?" How would you answer such a question? There might be resources out there that explain how some pieces in Google are ...
2
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5answers
346 views

Closest file match?

I am looking for a way to compare a set of files against a given file with each comparison giving me a "closeness" metric. I should then be able to order based upon the metric to find the closest ...
0
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3answers
429 views

How can I keep directories in sync

Context: I'm developing software that reproduce the functionality of Windows Home Server Drive Extender, where users use multiple hard disks to prevent data loss. The software exists since Dec-2009, ...
10
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11answers
2k views

Prefer algorithms to hand-written loops?

Which of the following to you find more readable? The hand-written loop: for (std::vector<Foo>::const_iterator it = vec.begin(); it != vec.end(); ++it) { bar.process(*it); } Or the ...
1
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1answer
170 views

How would you tackle a pattern-finding program?

Just to be clear, I don't think this should be question better suited for stackoverflow.com simply because there's not a single answer but a wide range of possible solutions, making this question far ...
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3answers
2k views

How do you choose a programming/data structure/algorithm book? [closed]

I really should not be mentioning the name of the book, but the first time I read it (during my under-grad days) I almost concluded that data structure was a bad course to pick. Which brings me to ...
34
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6answers
31k views

Can an algorithm be patented? [closed]

So can an algorithm be patented? I saw this statement which made me think: Everybody would abstain from patenting the improvements of contour dot algorithm for at least several years, say ...
6
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3answers
514 views

How can I design an anti-spam algorithm based on a web usage profile?

I've looked at other anti-spam algorithms, notably Reddit's, but they seem to be inadequate and naive: for example, only banning specific words (like "spam") that appear in the title of a post. How ...
6
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1answer
2k views

Natural Language Processing (NLP) open source algorithms [closed]

I am looking for a way to give an algorithm (service) a sentence, and it will tell me if its positive context or negative or even neutral. Does such a service exist?
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3answers
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An example of a beginner-level Algorithm, intermediate level Algorithm and a complex/expert level Algorithm?

I'd like to get a sense for the range of complexity that algorithms fall into. I think it would be interesting and helpful for those, like me, trying to better understand how algorithms are formulated ...
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5answers
4k views

Algorithm for Learning development [closed]

This is a fairly general question. I know a bit of Perl and Python and I am looking to learn programming in more depth so that once I get the hang of it I can start developing applications and then ...
10
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1answer
630 views

Algorithms: Find the best table to play (standing gambler problem)

Preface This is not code golf. I'm looking at an interesting problem and hoping to solicit comments and suggestions from my peers. This question is not about card counting (exclusively), rather, it ...
53
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16answers
5k views

Is big-O really that relevant when working in industry?

In every interview I have been in, I have been quizzed on mathematical analysis of complexity, including big-O notation. How relevant is big-O analysis to development in industry? How often do you ...
31
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12answers
12k views

Do I need to understand algorithms and data structures to be called a programmer? [closed]

It has been six years since I have been coding. Coding into all kinds of things like ActionScript, JavaScript, Java, PHP, Ajax, XML HTML, ASP, etc. I have used arrays, maps, linked lists, sets, etc ...
2
votes
3answers
472 views

shadow simulation from buildings

Is it possible to calculate shadow areas of buildings or simulate shadows of buildings in a city, using the heights of these buildings and the sun angle and azimuth? The basic light tracing concept ...
0
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1answer
70 views

Handling contacts imported from users email account

In my web application, I give the user the option to import all of his/her contacts from their email account, and then send out invites to all of these accounts or map the user to the existing ...
0
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1answer
809 views

question, the best data structure and algorithm

I have a question about implementing a data structure (with algorithm) that has these features: There are too many places (like stores), and each place can store too many items, I want to store ...
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4answers
4k views

Which algorithms and data structures should a developer absolutely know? [closed]

I want to be a successful enterprise Java developer. With what algorithms and data structures should I be well versed? What books would you recommend to me? To be a successful Java developer, do I ...
6
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4answers
1k views

What is a good way to brainstorm algorithms on a computer? [closed]

I'm looking for something that allows me to work out an algorithm on a computer similar to how I would do it on a whiteboard. At work, I have a huge whiteboard that I can use for this, but at home, I ...
24
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9answers
7k views

Are algorithm questions good interview questions? [closed]

I've had an argument recently with a fellow programmer. He was interviewing for a new position and was asked this question: Give a sequence of numbers starting at X and ending in Y but with one ...
9
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6answers
538 views

Quicksort and don't bother?

Especially when writing 'standard' (non-HPC) applications, do you consider what sorting algorithm to pick, or just settle with quicksort (which is what most libraries just call sort)? To some extent ...
3
votes
1answer
305 views

Should one write Big Oh complexity in the documentation of algorithms? [closed]

When writing or using an algorithm, should the Big Oh complexity be mentioned?