submit urlsubmit rss feedadd directory

article

In computer science, a search algorithm, broadly speaking, is an algorithm that takes a problem as input and returns a solution to the problem, usually after evaluating a number of possible solutions. Most of the algorithms studied by computer scientists that solve problems are kinds of search algorithms. The set of all possible solutions to a problem is called the search space. Brute-force search or "naïve"/uninformed search algorithms use the simplest, most intuitive method of searching through the search space, whereas informed search algorithms use heuristics to apply knowledge about the structure of the search space to try to reduce the amount of time spent searching.

Uninformed search


An uninformed search algorithm is one that does not take into account the specific nature of the problem. As such, they can be implemented in general, and then the same implementation can be used in a wide range of problems thanks to abstraction. The drawback is that most search spaces are extremely large, and an uninformed search (especially of a tree) will take a reasonable amount of time only for small examples. As such, to speed up the process, sometimes only an informed search will do.

List search

List search algorithms are perhaps the most basic kind of search algorithm. The goal is to find one element of a set by some key (perhaps containing other information related to the key). As this is a common problem in computer science, the computational complexity of these algorithms has been well studied. The simplest such algorithm is linear search, which simply examines each element of the list in order. It has expensive O(n) running time, where n is the number of items in the list, but can be used directly on any unprocessed list. A more sophisticated list search algorithm is binary search; it runs in O(log n) time. This is significantly better than linear search for large lists of data, but it requires that the list be sorted before searching (see sorting algorithm) and also be random access. Interpolation search is better than binary search for very large sorted lists with fairly even distributions. Grover's algorithm is a quantum algorithm that offers quadratic speedup over the classical linear search for unsorted lists.

More on [ Search algorithm ]


directory of related categories

 
directory of related topics

Computer Database Theory

 
Sorting_and_Searching RSS feed
eWeek - RSS Feeds

NetApp Reports Strong Financials
Wed, 21 May 2008 20:33:25 -0400
Year-over-year growth of 18 percent out-performs the rest of the storage market.... Take Control of Remote Computers. Support, configure and install applications and updates remotely for greater efficiency.
Salesforce.com Profit Rises, Lifts 2009 Estimates
Wed, 21 May 2008 20:27:10 -0400
Salesforce.com's first-quarter net income totaled $9.6 million, up from $730,000 in the year-ago period.... See how easy remote support can be. Try WebEx free! Deliver Support More Efficiently. Remotely Control Applications. Leap Securely through Firewalls!
Workday to Mobilize HCM
Wed, 21 May 2008 19:14:51 -0400
Workday's Web services-based architecture will help road warriors file expenses and other reports using mobile devices.... Attend WINDOWS EMBEDDED ACCELERATION WORKSHOPS Are you ready to learn how you can bring your next-generation embedded device to market faster?
HP-EDS Merger Could Bring Massive Job Cuts
Wed, 21 May 2008 18:57:01 -0400
One analyst group says it thinks HP may have to cut up to 50,000 jobs.... We Love Virtual Appliances SpamTitan for VMware 99% Spam Detection, Kaspersky AV, Anti Phishing,30 Free Evaluation,Download Now
Bugs Bite Apple iCal Application
Wed, 21 May 2008 18:42:51 -0400
Researchers at Core Security find three remotely exploitable bugs in iCal.... Custom Software Quote Custom Software Development. Get Free Quote.

The Seattle Times: Business & Technology

Instead of Yahoo, Microsoft spotlights aQuantive
Wed, 21 May 2008 09:21:06 -0700
The prospect of a Microsoft-Yahoo combination, with all its questions on how to "integrate" the two companies, is again bubbling to the...
Oil prices pass $135 after report of supply drop
Wed, 21 May 2008 18:20:23 -0700
Runaway oil prices blew past $130 a barrel for the first time Wednesday and kept going, while gasoline prices persisted in their own relentless climb, rising above $3.80 a gallon. Supply worries, rising demand and a slumping dollar are conspiring to make filling up the car - and paying for just about everything else - a growing burden for Americans.
Fed sharply lowers outlook for U.S. growth; sees higher inflation, jobless rate
Wed, 21 May 2008 16:32:32 -0700
The Federal Reserve today sharply lowered its projection for economic growth this year, citing blows from the housing and credit debacles...

NYT > Technology

Microsoft Offers Rebates to Shoppers Using Its Search
Thu, 22 May 2008 04:46:55 -0000
Microsoft is taking a new approach to jump-starting its search engine: offering rebates to people who use it to find and buy some products.
Google Says It Will Defend Competitive Rationale of a Yahoo Deal
Thu, 22 May 2008 04:49:29 -0000
How can Google, the Internet search and advertising giant, contend that teaming up with Yahoo in search ads would not invite an antitrust challenge?
Open-Source File Format Is to Be a Part of Microsoft Office
Thu, 22 May 2008 04:47:15 -0000
Under pressure from European regulators and others, Microsoft is to say it will give customers the ability to use documents in Open Document Format — the main rival to the Microsoft Word format.

CNN.com - Technology

Surprised astronomers catch a dying star
Wed, 21 May 2008 18:16:41 -0400
Read full story for latest details.
TVA vulnerable to hacking, GAO says
Wed, 21 May 2008 17:10:11 -0400
The nation's largest publicly owned utility company may be vulnerable to cyber attacks, according to a new report.
Professor makes breakthroughs, ballads
Wed, 21 May 2008 09:15:47 -0400
"Attracted by your gravity, your body's so compact / Pulling me inward, prepare for close contact," Boston University astronomer Alan Marscher sings in his song about a deep-space object known as a black hole.

NPR Topics: Technology

Nanotubes, Like Asbestos, Could Threaten Health
Wed, 21 May 2008 10:40:00 -0400
Tiny tubes made of carbon atoms have promised to revolutionize industry. But a new study in mice suggests that one kind of nanotube produces biological changes like those caused by asbestos.
Toyota Leads Race for 'Green' Cars
Wed, 21 May 2008 06:00:00 -0400
The sale of the one-millionth Prius emphasizes Toyota's early lead in hybrid vehicle sales. But Honda plans to introduce a low-cost hybrid car in the U.S. market early next year. And Nissan and GM will follow a year later.
Google, Apple Go Head to Head in Ultimate Frisbee
Tue, 20 May 2008 16:41:00 -0400
Every few weeks during the spring, stalwarts of the Internet economy — companies like Google, Apple, Facebook and Yahoo — meet on an open field to shout out their brand loyalties and throw things at each other. It's not the downturn in the economy that has blood pressures high. It's ultimate Frisbee.

BBC News | Technology | UK Edition

Rural homes dominate broadband UK
Wed, 21 May 2008 23:11:34 -0000
Rural households are now more likely to have a broadband connection than residents of towns, says Ofcom.
Microsoft offers cash back search
Wed, 21 May 2008 19:49:55 -0000
Microsoft is offering shoppers cash rebates to use its new service in a bid to close the gap on market leader Google
Net downloads to get age ratings
Wed, 21 May 2008 12:14:28 -0000
Games and videos downloaded from the web are to be policed by a voluntary age rating scheme.

Reuters Video: Technology

A tech 'renaissance' in Europe
Wed, 21 May 2008 14:51:13 -0400
May 21 - Central and Eastern Europe has quietly become a hub of innovation for start-ups and top tech companies alike.
Touchphones put finger on success
Wed, 21 May 2008 01:28:29 -0400
May 21 - Touchscreen mobile phones are the sector's next killer application, and Asian makers and consumers are joining the party.
The Google of Europe?
Tue, 20 May 2008 14:09:58 -0400
May 20 - A Slovenian start up called Zemanta is "feeling lucky" after winning international investment for its innovative technology.

AP Top Technology News At 12:47 a.m. EDT

'Indiana Jones' and the computer-generated jungle
By DERRIK J. LANG Thu, 22 May 2008 04:47:26 -0000
SAN FRANCISCO (AP) -- In these hallowed halls, Indiana Jones almost seems out of place. A banner with a two-dimensional cutout of the swashbuckling archaeologist swings through the lobby of Industrial Light and Magic, where life-size replicas of Darth Vader and Bobba Fett from "Star Wars" stand guard....
Facebook preparing for redesign to clear clutter
By MICHAEL LIEDTKE Wed, 21 May 2008 22:45:27 -0000
PALO ALTO, Calif. (AP) -- Having nearly tripled its audience and added about 20,000 new applications over the past year, Facebook Inc.'s popular online hangout is about to undergo a housecleaning....
Microsoft lures search traffic with cash rebates
By JESSICA MINTZ Wed, 21 May 2008 19:37:21 -0000
REDMOND, Wash. (AP) -- Microsoft Corp. is offering cash rebates when people make purchases after using its search engine as the software maker begins to reveal how it plans to take on Google Inc. following the failure of its $47.5 billion bid for Yahoo....

CNET News.com

HP introduces new 'green' label for products
Wed, 21 May 2008 21:00:00 -0700
The Eco Highlights label will flag the company's most environmentally friendly peripherals, like a completely recyclable printer.
GamePie: GameFly's social Facebook application
Wed, 21 May 2008 20:19:00 -0700
GameFly launches a Facebook application that allows gamers to share what they are currently playing; review and score games that they have played in the past; and make a wish list of games that they want to play in the future.
Carbon trading our way out of hunger crisis
Wed, 21 May 2008 18:05:00 -0700
A seemingly magical chemical combined with a carbon trading network is one company's hope for ending world hunger and reducing global warming.

 
Subscribe to Sorting_and_Searching RSS feed

directory of related sites

404 An Improved Comb Sort with Pre-defined Gap Table - The original comb sort is vulnerable to seriously degraded performance with certain repetitive input sequences. This variation addresses those problems and bounds worst case performance.
Meta Description: [ An Improved Comb Sort with Pre-Defined Gap Table. ]

Common comparison sorts - Explanation, algorithm analysis, empirical data, and source code for the bubble, heap, insertion, merge, quick, selection, and shell sorts.
Meta Description: [ Description, source code, algorithm analysis, and empirical results for bubble, heap, insertion, merge, quick, selection, and shell sorts. ]

Compact Guide to Sorting and Searching - Algorithms and data structures. Source code in C and VB is included. Demonstration applets in Java.
Meta Description: [ Algorithms for sorting and searching. ]

Comparison sort - From Wikipedia, the free encyclopedia. Definition, examples, lower bound.

500 Dictionary Implementation using Red and Black Tree - Documentation of a C++ project by Dogan Can and Serdar Kemal Balci.
Meta Description: [ A dictionary implementation in C++ ]

Discussion of Sorting Algorithms - A web tutorial by Mark Baker.

Exact string matching algorithms - Common pattern search approaches with C implementations.
Meta Description: [ EXACT STRING MATCHING ALGORITHMS Animation in Java ]

Fast Median Search - Overview of algorithms to find the median in a list of values; implementations and links are also provided.

500 Fast multi-pattern search - A fast algorithm for multi-pattern searching by Sun Wu

Fibonacci search in C - Fibonacci search and C sample code.
Meta Description: [ Free C implementation of the Fibonaccian search algorithm ]

FlashSort - Sorting by in place permutation with time complexity O(n) using an auxiliary vector. Papers, animations and implementations.
Meta Description: [ A newly developped fast in-situ permutation sort algorithm with time complexity O(n). ]

Fuzzy Search - Approximate search resources on ITman homepage.
Meta Description: [ fuzzy approximate search information retrieval ]

GNU libavl - Details of this collection of binary search tree and balanced tree library routines by Ben Pfaff. Etext in HTML/PDF/PS and source distribution.

Levenshtein Algorithm For Error-Tolerant Search - Resources on the Levenshtein Algorithm for fault-tolerant search. Website contains online demos and efficient implementations.
Meta Description: [ Resources on the Levenshtein Algorithm for fault-tolerant search. Website contains online-demos and efficient implementations. ]

Parallel and Sequential Sorting Algorithms - An explanation of the sorting algorithms Quicksort, Heapsort, Shellsort, Mergesort, sorting networks such as Odd-even transposition sort, Bitonic sort and parallel sorting algorithms for two-dimensional processor arrays. All including animations.
Meta Description: [ Description of sorting algorithms (course material), all including animations ]

Postman's Sort - A linear time general purpose sorting algorithm. Included is a description of the algorithm and downloadable executables for Windows computers.
Meta Description: [ Postman Sort Program and Consulting ]

500 Robsort Sorting Algorithm - An O(n!) algorithm with downloads for Win98 and Unix platforms.

404 RumAVL - An ANSI C implementation of threaded AVL trees.
Meta Description: [ freshmeat maintains the Web's largest index of Unix and cross-platform open source software. Thousands of applications are meticulously cataloged in the freshmeat database, and links to new code are added daily. ]

Search Algorithm - From Wikipedia, the free encyclopedia. Classification, summaries of the popular searching algorithms, links.

Search Methods in AI - Brief summary of fundamental problem space search algorithms.

Searching Algorithms - Overview of many sorting techniques and corresponding links.

Sequitur - Infers an hierarchical structure from a sequence of discrete symbols. Site includes examples, source code, description, publications, and an on-line demonstration.

404 sortchk - A simple test suite to measure the costs (in terms of needed comparisons and needed data moves) of different sorting algorithms. Unix sources.
Meta Description: [ freshmeat maintains the Web's largest index of Unix and cross-platform open source software. Thousands of applications are meticulously cataloged in the freshmeat database, and links to new code are added daily. ]

Sorting Algorithm - From Wikipedia, the free encyclopedia. Classification, summaries of the popular sorting algorithms, links.

Sorting Algorithm Examples - Collection of sorting algorithms in C
Meta Description: [ Description of sorting algorithms, and source code ]

Sorting Algorithms - Overview of many sorting techniques and corresponding links.

Sorting Algorithms Visualized - Applet visualizing various sorting algorithms, English version of Peter Weigel and Andreas Boltzmann applet.

Sorting and Searching Algorithms By Thomas Niemann. - Collection of algorithms for sorting and searching from arrays to B-Trees - theory, examples, implementation.

String Searching - From Wikipedia, the free encyclopedia. Definition, classification, common algorithms, links.

String Searching With Suffix Trees - Fast String Searching With Suffix Trees by Mark Nelson

Suffix Tree - ANSI C implementation of E. Ukkonen's algorithm that makes it convenient to do string matching against a data set in O(N) time. Includes source code, an interface in Perl, and a write-up.
Meta Description: [ ANSI C implementation of a Suffix Tree ]

Ternary Search Trees - Algorithm for search. PDF file and examples in C.

Three Dimensional Bubble Sort - A specification of a new 'bubble sort' in three or more dimesions, with illustrative images.

Understanding SoundEx Algorithms - Article describing and discussing the SoundEx searching algorithm and enhancements to make it more accurate. Includes SoundEx conversion form and Open licensed source code in C, JavaScript, and Perl.
Meta Description: [ SoundEx How to: Description of the SoundEx phonetic search index algorithm, differences between various versions used, and enhancements to the original patented version - source code in C, Perl, JavaScript, and VB included. - Creativyst, Inc. Docs - ]

WASA - A Java implementation of the Wealthy Adaptative Search Algorithm, a constraint-solving algorithm using a stochastic approach. Sourceforge/GPL.

Sorting_and_Searching related videos

LMai : Context based search, Artificial Intelligence

Sobha Renaissance Information Technologies announced a path breaking innovation in the realm of Artificial Intelligence applied on search engines called LMai (Latent Metonymical Analysis and Indexing). The event hosted by SRIT in Bangalore on May 07th 2007 at the Oberoi Hotel, MG Road was attended by key technology and business Media. Spokespersons from the company included Dr. Madhu Nambiar MD & CEO, Mr. Joseph N J Director Marketing, Dr. P S Ramkumar Executive Director iHCx and Syed Yasin R&D Project Lead.

 

HOMEADVERTISINGABOUT US

articlesartsbusinesscomputersgameshealthhospitalshomekids & teensnewsmobilephysiciansrecreationreferenceregionalscienceshoppingsocietysportsworld


Submit a Site About Become an Editor