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  • Multi-Precision Arithmetic on MIPS

    - by Rob
    Hi, I am just trying to implement multi-precision arithmetic on native MIPS. Assume that one 64-bit integer is in register $12 and $13 and another is in registers $14 and $15. The sum is to be placed in registers $10 and $11. The most significant word of the 64-bit integer is found in the even-numbered registers, and the least significant word is found in the odd-numbered registers. On the internet, it said, this is the shortest possible implementation. addu $11, $13, $15 # add least significant word sltu $10, $11, $15 # set carry-in bit addu $10, $10, $12 # add in first most significant word addu $10, $10, $14 # add in second most significant word I just wanna double check that I understand correctly. The sltu checks if the sum of the two least significant words is smaller or equal than one of the operands. If this is the case, than did a carry occur, is this right? To check if there occured a carry when adding the two most significant words and store the result in $9 I have to do: sltu $9, $10, $12 # set carry-in bit Does this make any sense?

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  • How to use MySQL geospatial extensions with spherical geometries

    - by Joshua
    Hi Everyone, I would like to store thousands of latitude/longitude points in a MySQL db. I was successful at setting up the tables and adding the data using the geospatial extensions where the column 'coord' is a Point(lat, lng). Problem: I want to quickly find the 'N' closest entries to latitude 'X' degrees and longitude 'Y' degrees. Since the Distance() function has not yet been implemented, I used GLength() function to calculate the distance between (X,Y) and each of the entries, sorting by ascending distance, and limiting to 'N' results. The problem is that this is not calculating shortest distance with spherical geometry. Which means if Y = 179.9 degrees, the list of closest entries will only include longitudes of starting at 179.9 and decreasing even though closer entries exist with longitudes increasing from -179.9. How does one typically handle the discontinuity in longitude when working with spherical geometries in databases? There has to be an easy solution to this, but I must just be searching for the wrong thing because I have not found anything helpful. Should I just forget the GLength() function and create my own function for calculating angular separation? If I do this, will it still be fast and take advantage of the geospatial extensions? Thanks! josh UPDATE: This is exactly what I am describing above. However, it is only for SQL Server. Apparently SQL Server has a Geometry and Geography datatypes. The geography does exactly what I need. Is there something similar in MySQL?

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  • Classical task-scheduling assignment

    - by Bruno
    I am working on a flight scheduling app (disclaimer: it's for a college project, so no code answers, please). Please read this question w/ a quantum of attention before answering as it has a lot of peculiarities :( First, some terminology issues: You have planes and flights, and you have to pair them up. For simplicity's sake, we'll assume that a plane is free as soon as the flight using it prior lands. Flights are seen as tasks: They have a duration They have dependencies They have an expected date/time for beginning Planes can be seen as resources to be used by tasks (or flights, in our terminology). Flights have a specific type of plane needed. e.g. flight 200 needs a plane of type B. Planes obviously are of one and only one specific type, e.g., Plane Airforce One is of type C. A "project" is the set of all the flights by an airline in a given time period. The functionality required is: Finding the shortest possible duration for a said project The earliest and latest possible start for a task (flight) The critical tasks, with basis on provided data, complete with identifiers of preceding tasks. Automatically pair up flights and planes, so as to get all flights paired up with a plane. (Note: the duration of flights is fixed) Get a Gantt diagram with the projects scheduling, in which all flights begin as early as possible, showing all previously referred data graphically (dependencies, time info, etc.) So the questions is: How in the world do I achieve this? Particularly: We are required to use a graph. What do the graph's edges and nodes respectively symbolise? Are we required to discard tasks to achieve the critical tasks set? If you could also recommend some algorithms for us to look up, that'd be great.

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  • C# Multiple constraints

    - by John
    I have an application with lots of generics and IoC. I have an interface like this: public interface IRepository<TType, TKeyType> : IRepo Then I have a bunch of tests for my different implementations of IRepository. Many of the objects have dependencies on other objects so for the purpose of testing I want to just grab one that is valid. I can define a separate method for each of them: public static EmailType GetEmailType() { return ContainerManager.Container.Resolve<IEmailTypeRepository>().GetList().FirstOrDefault(); } But I want to make this generic so it can by used to get any object from the repository it works with. I defined this: public static R GetItem<T, R>() where T : IRepository<R, int> { return ContainerManager.Container.Resolve<T>().GetList().FirstOrDefault(); } This works fine for the implementations that use an integer for the key. But I also have repositories that use string. So, I do this now: public static R GetItem<T, R, W>() where T : IRepository<R, W> This works fine. But I'd like to restrict 'W' to either int or string. Is there a way to do that? The shortest question is, can I constrain a generic parameter to one of multiple types?

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  • facebook Hacker cup: studious Student problem.

    - by smartmuki
    During the qualification round, the following question was asked: You've been given a list of words to study and memorize. Being a diligent student of language and the arts, you've decided to not study them at all and instead make up pointless games based on them. One game you've come up with is to see how you can concatenate the words to generate the lexicographically lowest possible string. Input As input for playing this game you will receive a text file containing an integer N, the number of word sets you need to play your game against. This will be followed by N word sets, each starting with an integer M, the number of words in the set, followed by M words. All tokens in the input will be separated by some whitespace and, aside from N and M, will consist entirely of lowercase letters. Output Your submission should contain the lexicographically shortest strings for each corresponding word set, one per line and in order. Constraints 1 <= N <= 100 1 <= M <= 9 1 <= all word lengths <= 10 Example input 5 6 facebook hacker cup for studious students 5 k duz q rc lvraw 5 mybea zdr yubx xe dyroiy 5 jibw ji jp bw jibw 5 uiuy hopji li j dcyi Example output cupfacebookforhackerstudentsstudious duzklvrawqrc dyroiymybeaxeyubxzdr bwjibwjibwjijp dcyihopjijliuiuy The program I wrote goes as: chomp($numberElements=<STDIN>); for(my $i=0; $i < $numberElements; $i++) { my $string; chomp ($string = <STDIN>); my @array=split(/\s+/,$string); my $number=shift @array; @sorted=sort @array; $sortedStr=join("",@sorted); push(@data,$sortedStr); } foreach (@data) { print "$_\n"; } The program gives the correct output for the given test cases but still facebook shows it to be incorrect. Is there something wrong with the program??

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  • Ruby integer to string key

    - by Gene
    A system I'm building needs to convert non-negative Ruby integers into shortest-possible UTF-8 string values. The only requirement on the strings is that their lexicographic order be identical to the natural order on integers. What's the best Ruby way to do this? We can assume the integers are 32 bits and the sign bit is 0. This is successful: (i >> 24).chr + ((i >> 16) & 0xff).chr + ((i >> 8) & 0xff).chr + (i & 0xff).chr But it appears to be 1) garbage-intense and 2) ugly. I've also looked at pack solutions, but these don't seem portable due to byte order. FWIW, the application is Redis hash field names. Building keys may be a performance bottleneck, but probably not. This question is mostly about the "Ruby way".

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  • Python, web log data mining for frequent patterns

    - by descent
    Hello! I need to develop a tool for web log data mining. Having many sequences of urls, requested in a particular user session (retrieved from web-application logs), I need to figure out the patterns of usage and groups (clusters) of users of the website. I am new to Data Mining, and now examining Google a lot. Found some useful info, i.e. querying Frequent Pattern Mining in Web Log Data seems to point to almost exactly similar studies. So my questions are: Are there any python-based tools that do what I need or at least smth similar? Can Orange toolkit be of any help? Can reading the book Programming Collective Intelligence be of any help? What to Google for, what to read, which relatively simple algorithms to use best? I am very limited in time (to around a week), so any help would be extremely precious. What I need is to point me into the right direction and the advice of how to accomplish the task in the shortest time. Thanks in advance!

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  • Code Golf: Connecting the dots

    - by ChristopheD
    Description: The input are multiple lines (terminated by a newline) which describe a 'field'. There are 'numbers' scattered across this field: the numbers always start at 1 they follow the ordering of the natural numbers: every 'next number' is incremented with 1 every number is surrounded by (at least) one whitespace on it's left and right Task: Draw lines between these numbers in their natural order (1 -> 2 -> 3 -> ...N) with the following characteristics: replace a number with a '+' character for horizontal lines: use '-' for vertical lines: use '|' going left and down or right and up: / going left and up or right and down: \ Important note: When drawing lines of type 4 and 5 you can assume that : (given points to connect with coordinates x1, y1 and x2, y2) distance(x1,x2) == distance(y1,y2). Have a look at the examples to see where you should 'attach' the lines. It is important to follow the order in which the dots are connected (newer lines can be drawn over older lines). Sample input 1 9 10 8 7 6 5 11 13 12 3 4 14 15 16 1 2 Sample output 1 /+ / | / | +/ +--+ | +\ | \ | \+ /+ | / | /+-------------+/ +---+ / | +--+ | + | +--------------------------+ Sample input 2 4 2 3 5 6 1 8 7 Sample output 2 /+ / | / | / | /+------------------+/ +--------+\ / \ +/ +--------------------------------------+ Winner: shortest solution (by code count). Input can be read via command line.

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  • Remove file from history completely

    - by Iain
    A colleague has done a few things I told them not to do: forked the origin repo online cloned the fork, added a file that shouldn't have been added to that local repo pushed this to their fork I've then: merged the changes from the fork and found the file I want to remove this from: my local repo the fork their local repo I have a solution for removing something from the history, taken from Remove file from git repository (history). What I need to know is, should my colleague also go through this, and will a subsequent push remove all info from the fork? (I'd like an alternative to just destroying the fork, as I'm not sure my colleague will do this) SOLUTION: This is the shortest way to get rid of the files: check .git/packed-refs - my problem was that I had there a refs/remotes/origin/master line for a remote repository, delete it, otherwise git won't remove those files (optional) git verify-pack -v .git/objects/pack/#{pack-name}.idx | sort -k 3 -n | tail -5 - to check for the largest files (optional) git rev-list --objects --all | grep a0d770a97ff0fac0be1d777b32cc67fe69eb9a98 - to check what files those are git filter-branch --index-filter 'git rm --cached --ignore-unmatch file_names' - to remove the file from all revisions rm -rf .git/refs/original/ - to remove git's backup git reflog expire --all --expire='0 days' - to expire all the loose objects (optional) git fsck --full --unreachable - to check if there are any loose objects git repack -A -d - repacking the pack git prune - to finally remove those objects

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  • How to improve this bash shell script for turning hardlinks into symlinks?

    - by MountainX
    This shell script is mostly the work of other people. It has gone through several iterations, and I have tweaked it slightly while also trying to fully understand how it works. I think I understand it now, but I don't have confidence to significantly alter it on my own and risk losing data when I run the altered version. So I would appreciate some expert guidance on how to improve this script. The changes I am seeking are: make it even more robust to any strange file names, if possible. It currently handles spaces in file names, but not newlines. I can live with that (because I try to find any file names with newlines and get rid of them). make it more intelligent about which file gets retained as the actual inode content and which file(s) become sym links. I would like to be able to choose to retain the file that is either a) the shortest path, b) the longest path or c) has the filename with the most alpha characters (which will probably be the most descriptive name). allow it to read the directories to process either from parameters passed in or from a file. optionally, write a long of all changes and/or all files not processed. Of all of these, #2 is the most important for me right now. I need to process some files with it and I need to improve the way it chooses which files to turn into symlinks. (I tried using things like the find option -depth without success.) Here's the current script: #!/bin/bash # clean up known problematic files first. ## find /home -type f -wholename '*Icon* ## *' -exec rm '{}' \; # Configure script environment # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ set -o nounset dir='/SOME/PATH/HERE/' # For each path which has multiple links # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # (except ones containing newline) last_inode= while IFS= read -r path_info do #echo "DEBUG: path_info: '$path_info'" inode=${path_info%%:*} path=${path_info#*:} if [[ $last_inode != $inode ]]; then last_inode=$inode path_to_keep=$path else printf "ln -s\t'$path_to_keep'\t'$path'\n" rm "$path" ln -s "$path_to_keep" "$path" fi done < <( find "$dir" -type f -links +1 ! -wholename '* *' -printf '%i:%p\n' | sort --field-separator=: ) # Warn about any excluded files # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ buf=$( find "$dir" -type f -links +1 -path '* *' ) if [[ $buf != '' ]]; then echo 'Some files not processed because their paths contained newline(s):'$'\n'"$buf" fi exit 0

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  • Top 20 Daily Deal Sites In India

    - by Damodhar
    If you have never heard of Groupon recently, you probably are not working in the tech industry because it is all over the blogosphere. After all, growing from zero to US$1.35 billion valuation in 18 months is pretty AMAZING. Inspired by this, the following bunch of Groupon clone’s are already rising in India. Definitely this business model is emerging and changes the way online shopping happens in India. SnapDeal SnapDeal features a Best deals Coupons at an unbeatable price on the best stuff to do, see, eat, and buy in our city. It provides vouchers and discounts in all the major cities like Delhi, Mumbai, Chennai and Bangalore. KhojGuru Exclusive Discount coupons from hundreds of brands and retailers. These discounts can be easily downloaded as an SMS on to the mobile phone or their print out can be taken. MyDala A platform which gets us great deals in our city.Leveraging the “power of group buying”. Group buying happens when like minded people come together to get deals that we can never get on our own as individuals. SoSasta Great place which would not only tell us about the hidden treasures of our city — but also made them affordable to us at the end of the month. DealsAndYou Deals and You is a group buying portal that features a daily deal on the best stuff in some of India’s leading cities. AajKaCatch Its concept is to provide you the most unique, useful and qualitative product at a very low price. So you can now shop without the hassles of clustered products. BindassBargain Bindaas Bargain offers a new deal every day! Great stuff ranging from cool gadgets, home theatres, luxury watches, smash games. MasthiDeals It get you a great deal on a great stuff to do, eat, buy or see in your city. They have a team of about 25 wonderful people working in Chennai office working side by side with folks in MasthiDeal’s other cities. Koovs Founded by a team of IIT alumni who have brought in their expertise from the internet industry. Koovs is a Bangalore based start up and one point solution for all your desires. Taggle It brings you a variety of offers from some of the most respected brands in the country.This website uses collective buying to create a win-win for local businesses and their customers. BuzzInTown Buzzintown.com is a portal owned by Wortal Inc. There are a US headquartered company, with a presence pan-India through their India subsidiary, managed by a vastly experienced set of global leaders from the media, entertainment and technology industries. BuyThePrice It lines up the best win – win deals for both consumers and vendors and also ensures that each of the orders are dispatched in the shortest time possible. 24HoursLoot 24hoursLoot is an online store for selling a new t-shirt (sometime other products) everyday at deep discounted price in limited quantity/stock. DealMagic Customers get exposure to the best their city has to offer, at unbeatable prices (50-90% off).  We never feature more than one business on our website on any given day, so we have to be very very selective on who gets featured. Dealivore ICUMI Technologies Pvt Ltd is the company operating the Dealivore service. Founded in December 2009, ICUMI is privately owned and funded. LootMore An online store that exclusively focuses on selling cool quality stuff at cheap prices. Here you’ll always find the latest and greatest brands at prices you can afford. Foodome The deals features the best coupons at an unbeatable price on restaurants, fine dining on where to spend your birthday party.They provide coupon only in Chennai as of now. Top Online Shopping Sites- Nation Wide ebay.in eBay is The World’s Online Marketplace, enabling trade on a local, national and international basis. With a diverse and passionate community of individuals and small businesses, eBay offers an online platform where millions of items are traded each day. FutureBazzar Future Group, led by its founder and Group CEO, Mr. Kishore Biyani, is one of India’s leading business houses with multiple businesses spanning across the consumption space. TradeUs Launched in July 2009 and in a short span of time it has turned into one of India’s foremost shopping portals setting the Indian e-commerce abode aflame. BigShoeBazzar (BSB) is the largest online authorized shoe store in South Asia. Croma Promoted by Infiniti Retail Ltd, a 100% subsidiary of Tata Sons.One of the world’s leading retailers, ensuring that you buy nothing but the best. This article titled,Top 20 Daily Deal Sites In India, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • Oracle Database 12c Spatial: Vector Performance Acceleration

    - by Okcan Yasin Saygili-Oracle
    Most business information has a location component, such as customer addresses, sales territories and physical assets. Businesses can take advantage of their geographic information by incorporating location analysis and intelligence into their information systems. This allows organizations to make better decisions, respond to customers more effectively, and reduce operational costs – increasing ROI and creating competitive advantage. Oracle Database, the industry’s most advanced database,  includes native location capabilities, fully integrated in the kernel, for fast, scalable, reliable and secure spatial and massive graph applications. It is a foundation for deploying enterprise-wide spatial information systems and locationenabled business applications. Developers can extend existing Oracle-based tools and applications, since they can easily incorporate location information directly in their applications, workflows, and services. Spatial Features The geospatial data features of Oracle Spatial and Graph option support complex geographic information systems (GIS) applications, enterprise applications and location services applications. Oracle Spatial and Graph option extends the spatial query and analysis features included in every edition of Oracle Database with the Oracle Locator feature, and provides a robust foundation for applications that require advanced spatial analysis and processing in the Oracle Database. It supports all major spatial data types and models, addressing challenging business-critical requirements from various industries, including transportation, utilities, energy, public sector, defense and commercial location intelligence. Network Data Model Graph Features The Network Data Model graph explicitly stores and maintains a persistent data model withnetwork connectivity and provides network analysis capability such as shortest path, nearest neighbors, within cost and reachability. It loads partitioned networks into memory on demand, overcomingthe limitations of in-memory analysis. Partitioning massive networks into manageable sub-networkssimplifies the network analysis. RDF Semantic Graph Features RDF Semantic Graph has native support for World Wide Web Consortium standards. It has open, scalable, and secure features for storing RDF/OWL ontologies anddata; native inference with OWL 2, SKOS and user-defined rules; and querying RDF/OWL data withSPARQL 1.1, Java APIs, and SPARQLgraph patterns in SQL. Video: Oracle Spatial and Graph Overview Oracle spatial is embeded on oracle database product. So ,we can use oracle installer (OUI).The Oracle Universal Installer (OUI) is used to install Oracle Database software. OUI is a graphical user interface utility that enables you to view the Oracle software that is installed on your machine, install new Oracle Database software, and delete Oracle software that you no longer need to use. Online Help is available to guide you through the installation process. One of the installation options is to create a database. If you select database creation, OUI automatically starts Oracle Database Configuration Assistant (DBCA) to guide you through the process of creating and configuring a database. If you do not create a database during installation, you must invoke DBCA after you have installed the software to create a database. You can also use DBCA to create additional databases. For installing Oracle Database 12c you may check the Installing Oracle Database Software and Creating a Database tutorial under the Oracle Database 12c 2-Day DBA Series.You can always check if spatial is available in your database using  "select comp_id, version, status, comp_name from dba_registry where comp_id='SDO';"   One of the most notable improvements with Oracle Spatial and Graph 12c can be seen in performance increases in vector data operations. Enabling the Spatial Vector Acceleration feature (available with the Spatial option) dramatically improves the performance of commonly used vector data operations, such as sdo_distance, sdo_aggr_union, and sdo_inside. With 12c, these operations also run more efficiently in parallel than in prior versions through the use of metadata caching. For organizations that have been facing processing limitations, these enhancements enable developers to make a small set of configuration changes and quickly realize significant performance improvements. Results include improved index performance, enhanced geometry engine performance, optimized secondary filter optimizations for Spatial operators, and improved CPU and memory utilization for many advanced vector functions. Vector performance acceleration is especially beneficial when using Oracle Exadata Database Machine and other large-scale systems. Oracle Spatial and Graph vector performance acceleration builds on general improvements available to all SDO_GEOMETRY operations in these areas: Caching of index metadata, Concurrent update mechanisms, and Optimized spatial predicate selectivity and cost functions. These optimizations enable more efficient use of: CPU, Memory, and Partitioning Resulting in substantial query performance improvements.UsageTo accelerate the performance of spatial operators, it is recommended that you set the SPATIAL_VECTOR_ACCELERATION database system parameter to the value TRUE. (This parameter is authorized for use only by licensed Oracle Spatial users, and its default value is FALSE.) You can set this parameter for the whole system or for a single session. To set the value for the whole system, do either of the following:Enter the following statement from a suitably privileged account:   ALTER SYSTEM SET SPATIAL_VECTOR_ACCELERATION = TRUE;Add the following to the database initialization file (xxxinit.ora):   SPATIAL_VECTOR_ACCELERATION = TRUE;To set the value for the current session, enter the following statement from a suitably privileged account:   ALTER SESSION SET SPATIAL_VECTOR_ACCELERATION = TRUE; Checkout the complete list of new features on Oracle.com @ http://www.oracle.com/technetwork/database/options/spatialandgraph/overview/index.html Spatial and Graph Data Sheet (PDF) Spatial and Graph White Paper (PDF)

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  • College Courses through distance learning

    - by Matt
    I realize this isn't really a programming question, but didn't really know where to post this in the stackexchange and because I am a computer science major i thought id ask here. This is pretty unique to the programmer community since my degree is about 95% programming. I have 1 semester left, but i work full time. I would like to finish up in December, but to make things easier i like to take online classes whenever I can. So, my question is does anyone know of any colleges that offer distance learning courses for computer science? I have been searching around and found a few potential classes, but not sure yet. I would like to gather some classes and see what i can get approval for. Class I need: Only need one C SC 437 Geometric Algorithms C SC 445 Algorithms C SC 473 Automata Only need one C SC 452 Operating Systems C SC 453 Compilers/Systems Software While i only need of each of the above courses i still need to take two more electives. These also have to be upper 400 level classes. So i can take multiple in each category. Some other classes I can take are: CSC 447 - Green Computing CSC 425 - Computer Networking CSC 460 - Database Design CSC 466 - Computer Security I hoping to take one or two of these courses over the summer. If not, then online over the regular semester would be ok too. Any help in helping find these classes would be awesome. Maybe you went to a college that offered distance learning. Some of these classes may be considered to be graduate courses too. Descriptions are listed below if you need. Thanks! Descriptions Computer Security This is an introductory course covering the fundamentals of computer security. In particular, the course will cover basic concepts of computer security such as threat models and security policies, and will show how these concepts apply to specific areas such as communication security, software security, operating systems security, network security, web security, and hardware-based security. Computer Networking Theory and practice of computer networks, emphasizing the principles underlying the design of network software and the role of the communications system in distributed computing. Topics include routing, flow and congestion control, end-to-end protocols, and multicast. Database Design Functions of a database system. Data modeling and logical database design. Query languages and query optimization. Efficient data storage and access. Database access through standalone and web applications. Green Computing This course covers fundamental principles of energy management faced by designers of hardware, operating systems, and data centers. We will explore basic energy management option in individual components such as CPUs, network interfaces, hard drives, memory. We will further present the energy management policies at the operating system level that consider performance vs. energy saving tradeoffs. Finally we will consider large scale data centers where energy management is done at multiple layers from individual components in the system to shutting down entries subset of machines. We will also discuss energy generation and delivery and well as cooling issues in large data centers. Compilers/Systems Software Basic concepts of compilation and related systems software. Topics include lexical analysis, parsing, semantic analysis, code generation; assemblers, loaders, linkers; debuggers. Operating Systems Concepts of modern operating systems; concurrent processes; process synchronization and communication; resource allocation; kernels; deadlock; memory management; file systems. Algorithms Introduction to the design and analysis of algorithms: basic analysis techniques (asymptotics, sums, recurrences); basic design techniques (divide and conquer, dynamic programming, greedy, amortization); acquiring an algorithm repertoire (sorting, median finding, strong components, spanning trees, shortest paths, maximum flow, string matching); and handling intractability (approximation algorithms, branch and bound). Automata Introduction to models of computation (finite automata, pushdown automata, Turing machines), representations of languages (regular expressions, context-free grammars), and the basic hierarchy of languages (regular, context-free, decidable, and undecidable languages). Geometric Algorithms The study of algorithms for geometric objects, using a computational geometry approach, with an emphasis on applications for graphics, VLSI, GIS, robotics, and sensor networks. Topics may include the representation and overlaying of maps, finding nearest neighbors, solving linear programming problems, and searching geometric databases.

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  • Contricted A* problem

    - by Ragekit
    I've got a little problem with an A* algorithm that I need to constrict a little bit. Basically : I use an A* to find the shortest path between 2 randomly placed room in 3D space, and then build a corridor between them. The problem I found is that sometimes it makes chimney like corridors that are not ideal, so I constrict the A* so that if the last movement was up or down, you go sideways. Everything is fine, but in some corner cases, it fails to find a path (when there is obviously one). Like here between the blue and red dot : (i'm in unity btw, but i don't think it matters) Here is the code of the actual A* (a bit long, and some redundency) while(current != goal) { //add stair up / stair down foreach(Node<GridUnit> test in current.Neighbors) { if(!test.Data.empty && test != goal) continue; //bug at arrival; if(test == goal && penul !=null) { Vector3 currentDiff = current.Data.bounds.center - test.Data.bounds.center; if(!Mathf.Approximately(currentDiff.y,0)) { //wanna drop on the last if(!coplanar(test.Data.bounds.center,current.Data.bounds.center,current.Data.parentUnit.bounds.center,to.Data.bounds.center)) { continue; } else { if(Mathf.Approximately(to.Data.bounds.center.x, current.Data.parentUnit.bounds.center.x) && Mathf.Approximately(to.Data.bounds.center.z, current.Data.parentUnit.bounds.center.z)) { continue; } } } } if(current.Data.parentUnit != null) { Vector3 previousDiff = current.Data.parentUnit.bounds.center - current.Data.bounds.center; Vector3 currentDiff = current.Data.bounds.center - test.Data.bounds.center; if(!Mathf.Approximately(previousDiff.y,0)) { if(!Mathf.Approximately(currentDiff.y,0)) { //you wanna drop now : continue; } if(current.Data.parentUnit.parentUnit != null) { if(!coplanar(test.Data.bounds.center,current.Data.bounds.center,current.Data.parentUnit.bounds.center,current.Data.parentUnit.parentUnit.bounds.center)) { continue; }else { if(Mathf.Approximately(test.Data.bounds.center.x, current.Data.parentUnit.parentUnit.bounds.center.x) && Mathf.Approximately(test.Data.bounds.center.z, current.Data.parentUnit.parentUnit.bounds.center.z)) { continue; } } } } } g = current.Data.g + HEURISTIC(current.Data,test.Data); h = HEURISTIC(test.Data,goal.Data); f = g + h; if(open.Contains(test) || closed.Contains(test)) { if(test.Data.f > f) { //found a shorter path going passing through that point test.Data.f = f; test.Data.g = g; test.Data.h = h; test.Data.parentUnit = current.Data; } } else { //jamais rencontré test.Data.f = f; test.Data.h = h; test.Data.g = g; test.Data.parentUnit = current.Data; open.Add(test); } } closed.Add (current); if(open.Count == 0) { Debug.Log("nothingfound"); //nothing more to test no path found, stay to from; List<GridUnit> r = new List<GridUnit>(); r.Add(from.Data); return r; } //sort open from small to biggest travel cost open.Sort(delegate(Node<GridUnit> x, Node<GridUnit> y) { return (int)(x.Data.f-y.Data.f); }); //get the smallest travel cost node; Node<GridUnit> smallest = open[0]; current = smallest; open.RemoveAt(0); } //build the path going backward; List<GridUnit> ret = new List<GridUnit>(); if(penul != null) { ret.Insert(0,to.Data); } GridUnit cur = goal.Data; ret.Insert(0,cur); do{ cur = cur.parentUnit; ret.Insert(0,cur); } while(cur != from.Data); return ret; You see at the start of the foreach i constrict the A* like i said. If you have any insight it would be cool. Thanks

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  • Constrained A* problem

    - by Ragekit
    I've got a little problem with an A* algorithm that I need to Constrained a little bit. Basically : I use an A* to find the shortest path between 2 randomly placed room in 3D space, and then build a corridor between them. The problem I found is that sometimes it makes chimney like corridors that are not ideal, so I constrict the A* so that if the last movement was up or down, you go sideways. Everything is fine, but in some corner cases, it fails to find a path (when there is obviously one). Like here between the blue and red dot : (i'm in unity btw, but i don't think it matters) Here is the code of the actual A* (a bit long, and some redundency) while(current != goal) { //add stair up / stair down foreach(Node<GridUnit> test in current.Neighbors) { if(!test.Data.empty && test != goal) continue; //bug at arrival; if(test == goal && penul !=null) { Vector3 currentDiff = current.Data.bounds.center - test.Data.bounds.center; if(!Mathf.Approximately(currentDiff.y,0)) { //wanna drop on the last if(!coplanar(test.Data.bounds.center,current.Data.bounds.center,current.Data.parentUnit.bounds.center,to.Data.bounds.center)) { continue; } else { if(Mathf.Approximately(to.Data.bounds.center.x, current.Data.parentUnit.bounds.center.x) && Mathf.Approximately(to.Data.bounds.center.z, current.Data.parentUnit.bounds.center.z)) { continue; } } } } if(current.Data.parentUnit != null) { Vector3 previousDiff = current.Data.parentUnit.bounds.center - current.Data.bounds.center; Vector3 currentDiff = current.Data.bounds.center - test.Data.bounds.center; if(!Mathf.Approximately(previousDiff.y,0)) { if(!Mathf.Approximately(currentDiff.y,0)) { //you wanna drop now : continue; } if(current.Data.parentUnit.parentUnit != null) { if(!coplanar(test.Data.bounds.center,current.Data.bounds.center,current.Data.parentUnit.bounds.center,current.Data.parentUnit.parentUnit.bounds.center)) { continue; }else { if(Mathf.Approximately(test.Data.bounds.center.x, current.Data.parentUnit.parentUnit.bounds.center.x) && Mathf.Approximately(test.Data.bounds.center.z, current.Data.parentUnit.parentUnit.bounds.center.z)) { continue; } } } } } g = current.Data.g + HEURISTIC(current.Data,test.Data); h = HEURISTIC(test.Data,goal.Data); f = g + h; if(open.Contains(test) || closed.Contains(test)) { if(test.Data.f > f) { //found a shorter path going passing through that point test.Data.f = f; test.Data.g = g; test.Data.h = h; test.Data.parentUnit = current.Data; } } else { //jamais rencontré test.Data.f = f; test.Data.h = h; test.Data.g = g; test.Data.parentUnit = current.Data; open.Add(test); } } closed.Add (current); if(open.Count == 0) { Debug.Log("nothingfound"); //nothing more to test no path found, stay to from; List<GridUnit> r = new List<GridUnit>(); r.Add(from.Data); return r; } //sort open from small to biggest travel cost open.Sort(delegate(Node<GridUnit> x, Node<GridUnit> y) { return (int)(x.Data.f-y.Data.f); }); //get the smallest travel cost node; Node<GridUnit> smallest = open[0]; current = smallest; open.RemoveAt(0); } //build the path going backward; List<GridUnit> ret = new List<GridUnit>(); if(penul != null) { ret.Insert(0,to.Data); } GridUnit cur = goal.Data; ret.Insert(0,cur); do{ cur = cur.parentUnit; ret.Insert(0,cur); } while(cur != from.Data); return ret; You see at the start of the foreach i constrict the A* like i said. If you have any insight it would be cool. Thanks

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  • 2d trajectory planning of a spaceship with physics.

    - by egarcia
    I'm implementing a 2D game with ships in space. In order to do it, I'm using LÖVE, which wraps Box2D with Lua. But I believe that my question can be answered by anyone with a greater understanding of physics than myself - so pseudo code is accepted as a response. My problem is that I don't know how to move my spaceships properly on a 2D physics-enabled world. More concretely: A ship of mass m is located at an initial position {x, y}. It has an initial velocity vector of {vx, vy} (can be {0,0}). The objective is a point in {xo,yo}. The ship has to reach the objective having a velocity of {vxo, vyo} (or near it), following the shortest trajectory. There's a function called update(dt) that is called frequently (i.e. 30 times per second). On this function, the ship can modify its position and trajectory, by applying "impulses" to itself. The magnitude of the impulses is binary: you can either apply it in a given direction, or not to apply it at all). In code, it looks like this: def Ship:update(dt) m = self:getMass() x,y = self:getPosition() vx,vy = self.getLinearVelocity() xo,yo = self:getTargetPosition() vxo,vyo = self:getTargetVelocity() thrust = self:getThrust() if(???) angle = ??? self:applyImpulse(math.sin(angle)*thrust, math.cos(angle)*thrust)) end end The first ??? is there to indicate that in some occasions (I guess) it would be better to "not to impulse" and leave the ship "drift". The second ??? part consists on how to calculate the impulse angle on a given dt. We are in space, so we can ignore things like air friction. Although it would be very nice, I'm not looking for someone to code this for me; I put the code there so my problem is clearly understood. What I need is an strategy - a way of attacking this. I know some basic physics, but I'm no expert. For example, does this problem have a name? That sort of thing. Thanks a lot.

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  • how to change a button into a imagebutton in asp.net c#

    - by sweetsecret
    How to change the button into image button... the button in the beginning has "Pick a date" when clicked a calender pops out and the when a date is selected a label at the bottom reading the date comes in and the text on the button changes to disabled... i want to palce a imagebutton having a image icon of the calender and rest of the function will be the same.... the code as follows: using System; using System.Collections.Generic; using System.ComponentModel; using System.Text; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; [assembly: TagPrefix("DatePicker", "EWS")] namespace EclipseWebSolutions.DatePicker { [DefaultProperty("Text")] [ToolboxData("<{0}:DatePicker runat=server")] [DefaultEvent("SelectionChanged")] [ValidationProperty("TextValue")] public class DatePicker : WebControl, INamingContainer { #region Properties public TextBox txtDate = new TextBox(); public Calendar calDate = new Calendar(); public Button btnDate = new Button(); public Panel pnlCalendar = new Panel(); private enum ViewStateConstants { ValidationGroup, RegularExpression, ErrorMessage, RegExText, CalendarPosition, FormatString, ExpandLabel, CollapseLabel, ApplyDefaultStyle, CausesValidation, } /// <summary> /// Defines the available display modes of this calendar. /// </summary> public enum CalendarDisplay { DisplayRight, DisplayBelow } /// <summary> /// Where to display the popup calendar. /// </summary> [Category("Behaviour")] [Localizable(true)] public CalendarDisplay CalendarPosition { get { if (ViewState[ViewStateConstants.CalendarPosition.ToString()] == null) { ViewState[ViewStateConstants.CalendarPosition.ToString()] = CalendarDisplay.DisplayRight; } return (CalendarDisplay)ViewState[ViewStateConstants.CalendarPosition.ToString()]; } set { ViewState[ViewStateConstants.CalendarPosition.ToString()] = value; } } /// <summary> /// Text version of the control's value, for use by ASP.NET validators. /// </summary> public string TextValue { get { return txtDate.Text; } } /// <summary> /// Holds the current date value of this control. /// </summary> [Category("Behaviour")] [Localizable(true)] [Bindable(true, BindingDirection.TwoWay)] public DateTime DateValue { get { try { if (txtDate.Text == "") return DateTime.MinValue; DateTime val = DateTime.Parse(txtDate.Text); return val; } catch (ArgumentNullException) { return DateTime.MinValue; } catch (FormatException) { return DateTime.MinValue; } } set { if (value == DateTime.MinValue) { txtDate.Text = ""; } else { txtDate.Text = value.ToShortDateString(); } } } [Category("Behavior"), Themeable(false), DefaultValue("")] public virtual string ValidationGroup { get { if (ViewState[ViewStateConstants.ValidationGroup.ToString()] == null) { return string.Empty; } else { return (string)ViewState[ViewStateConstants.ValidationGroup.ToString()]; } } set { ViewState[ViewStateConstants.ValidationGroup.ToString()] = value; } } /// <summary> /// The label of the exand button. Shown when the calendar is hidden. /// </summary> [Bindable(true)] [Category("Appearance")] [DefaultValue("PickDate")] [Localizable(true)] public string ExpandButtonLabel { get { String s = (String)ViewState[ViewStateConstants.ExpandLabel.ToString()]; return ((s == null) ? "PickDate" : s); } set { ViewState[ViewStateConstants.ExpandLabel.ToString()] = value; } } /// <summary> /// The label of the collapse button. Shown when the calendar is visible. /// </summary> [Bindable(true)] [Category("Appearance")] [DefaultValue("Disabled")] [Localizable(true)] public string CollapseButtonLabel { get { String s = (String)ViewState[ViewStateConstants.CollapseLabel.ToString()]; return ((s == null) ? "Disabled" : s); } set { ViewState[ViewStateConstants.CollapseLabel.ToString()] = value; } } /// <summary> /// Whether to apply the default style. Disable this if you want to apply a custom style, or to use themes and skins /// to style the control. /// </summary> [Category("Appearance")] [DefaultValue(true)] [Localizable(true)] public bool ApplyDefaultStyle { get { if (ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()] == null) { ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()] = true; } return (bool)ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()]; } set { ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()] = value; } } /// <summary> /// Causes Validation /// </summary> [Category("Appearance")] [DefaultValue(false)] [Localizable(false)] public bool CausesValidation { get { if (ViewState[ViewStateConstants.CausesValidation.ToString()] == null) { ViewState[ViewStateConstants.CausesValidation.ToString()] = false; } return (bool)ViewState[ViewStateConstants.CausesValidation.ToString()]; } set { ViewState[ViewStateConstants.CausesValidation.ToString()] = value; btnDate.CausesValidation = value; } } #endregion #region Events /// <summary> /// A day was selected from the calendar control. /// </summary> public event EventHandler SelectionChanged; protected virtual void OnSelectionChanged() { if (SelectionChanged != null) // only raise the event if someone is listening. { SelectionChanged(this, EventArgs.Empty); } } #endregion #region Event Handlers /// <summary> /// The +/- button was clicked. /// </summary> protected void btnDate_Click(object sender, System.EventArgs e) { if (!calDate.Visible) { // expand the calendar calDate.Visible = true; txtDate.Enabled = false; btnDate.Text = CollapseButtonLabel; if (DateValue != DateTime.MinValue) { calDate.SelectedDate = DateValue; calDate.VisibleDate = DateValue; } } else { // collapse the calendar calDate.Visible = false; txtDate.Enabled = true; btnDate.Text = ExpandButtonLabel; } } /// <summary> /// A date was selected from the calendar. /// </summary> protected void calDate_SelectionChanged(object sender, System.EventArgs e) { calDate.Visible = false; txtDate.Visible = true; btnDate.Text = ExpandButtonLabel; txtDate.Enabled = true; txtDate.Text = calDate.SelectedDate.ToShortDateString(); OnSelectionChanged(); } #endregion /// <summary> /// Builds the contents of this control. /// </summary> protected override void CreateChildControls() { btnDate.Text = ExpandButtonLabel; btnDate.CausesValidation = CausesValidation; txtDate.ID = "txtDate"; calDate.Visible = false; if (ApplyDefaultStyle) { calDate.BackColor = System.Drawing.Color.White; calDate.BorderColor = System.Drawing.Color.FromArgb(10066329); calDate.CellPadding = 2; calDate.DayNameFormat = DayNameFormat.Shortest; calDate.Font.Name = "Verdana"; calDate.Font.Size = FontUnit.Parse("8pt"); calDate.ForeColor = System.Drawing.Color.Black; calDate.Height = new Unit(150, UnitType.Pixel); calDate.Width = new Unit(180, UnitType.Pixel); calDate.DayHeaderStyle.BackColor = System.Drawing.Color.FromArgb(228, 228, 228); calDate.DayHeaderStyle.Font.Size = FontUnit.Parse("7pt"); calDate.TitleStyle.Font.Bold = true; calDate.WeekendDayStyle.BackColor = System.Drawing.Color.FromArgb(255, 255, 204); } ConnectEventHandlers(); pnlCalendar.Controls.Add(calDate); pnlCalendar.Style["position"] = "absolute"; pnlCalendar.Style["filter"] = "alpha(opacity=95)"; pnlCalendar.Style["-moz-opacity"] = ".95"; pnlCalendar.Style["opacity"] = ".95"; pnlCalendar.Style["z-index"] = "2"; pnlCalendar.Style["background-color"] = "White"; if (CalendarPosition == CalendarDisplay.DisplayBelow) { pnlCalendar.Style["margin-top"] = "27px"; } else { pnlCalendar.Style["display"] = "inline"; } Controls.Add(txtDate); Controls.Add(pnlCalendar); Controls.Add(btnDate); base.CreateChildControls(); } /// <summary> /// Render the contents of this control. /// </summary> /// <param name="output">The HtmlTextWriter to use.</param> protected override void RenderContents(HtmlTextWriter output) { switch (CalendarPosition) { case CalendarDisplay.DisplayRight: { txtDate.RenderControl(output); btnDate.RenderControl(output); pnlCalendar.RenderControl(output); break; } case CalendarDisplay.DisplayBelow: { pnlCalendar.RenderControl(output); txtDate.RenderControl(output); btnDate.RenderControl(output); break; } } } /// <summary> /// Connect event handlers to events. /// </summary> private void ConnectEventHandlers() { btnDate.Click += new System.EventHandler(btnDate_Click); calDate.SelectionChanged += new System.EventHandler(calDate_SelectionChanged); } } } using System; using System.Collections.Generic; using System.ComponentModel; using System.Text; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; [assembly: TagPrefix("DatePicker", "EWS")] namespace EclipseWebSolutions.DatePicker { [DefaultProperty("Text")] [ToolboxData("<{0}:DatePicker runat=server")] [DefaultEvent("SelectionChanged")] [ValidationProperty("TextValue")] public class DatePicker : WebControl, INamingContainer { #region Properties public TextBox txtDate = new TextBox(); public Calendar calDate = new Calendar(); public Button btnDate = new Button(); public Panel pnlCalendar = new Panel(); private enum ViewStateConstants { ValidationGroup, RegularExpression, ErrorMessage, RegExText, CalendarPosition, FormatString, ExpandLabel, CollapseLabel, ApplyDefaultStyle, CausesValidation, } /// <summary> /// Defines the available display modes of this calendar. /// </summary> public enum CalendarDisplay { DisplayRight, DisplayBelow } /// <summary> /// Where to display the popup calendar. /// </summary> [Category("Behaviour")] [Localizable(true)] public CalendarDisplay CalendarPosition { get { if (ViewState[ViewStateConstants.CalendarPosition.ToString()] == null) { ViewState[ViewStateConstants.CalendarPosition.ToString()] = CalendarDisplay.DisplayRight; } return (CalendarDisplay)ViewState[ViewStateConstants.CalendarPosition.ToString()]; } set { ViewState[ViewStateConstants.CalendarPosition.ToString()] = value; } } /// <summary> /// Text version of the control's value, for use by ASP.NET validators. /// </summary> public string TextValue { get { return txtDate.Text; } } /// <summary> /// Holds the current date value of this control. /// </summary> [Category("Behaviour")] [Localizable(true)] [Bindable(true, BindingDirection.TwoWay)] public DateTime DateValue { get { try { if (txtDate.Text == "") return DateTime.MinValue; DateTime val = DateTime.Parse(txtDate.Text); return val; } catch (ArgumentNullException) { return DateTime.MinValue; } catch (FormatException) { return DateTime.MinValue; } } set { if (value == DateTime.MinValue) { txtDate.Text = ""; } else { txtDate.Text = value.ToShortDateString(); } } } [Category("Behavior"), Themeable(false), DefaultValue("")] public virtual string ValidationGroup { get { if (ViewState[ViewStateConstants.ValidationGroup.ToString()] == null) { return string.Empty; } else { return (string)ViewState[ViewStateConstants.ValidationGroup.ToString()]; } } set { ViewState[ViewStateConstants.ValidationGroup.ToString()] = value; } } /// <summary> /// The label of the exand button. Shown when the calendar is hidden. /// </summary> [Bindable(true)] [Category("Appearance")] [DefaultValue("PickDate")] [Localizable(true)] public string ExpandButtonLabel { get { String s = (String)ViewState[ViewStateConstants.ExpandLabel.ToString()]; return ((s == null) ? "PickDate" : s); } set { ViewState[ViewStateConstants.ExpandLabel.ToString()] = value; } } /// <summary> /// The label of the collapse button. Shown when the calendar is visible. /// </summary> [Bindable(true)] [Category("Appearance")] [DefaultValue("Disabled")] [Localizable(true)] public string CollapseButtonLabel { get { String s = (String)ViewState[ViewStateConstants.CollapseLabel.ToString()]; return ((s == null) ? "Disabled" : s); } set { ViewState[ViewStateConstants.CollapseLabel.ToString()] = value; } } /// <summary> /// Whether to apply the default style. Disable this if you want to apply a custom style, or to use themes and skins /// to style the control. /// </summary> [Category("Appearance")] [DefaultValue(true)] [Localizable(true)] public bool ApplyDefaultStyle { get { if (ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()] == null) { ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()] = true; } return (bool)ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()]; } set { ViewState[ViewStateConstants.ApplyDefaultStyle.ToString()] = value; } } /// <summary> /// Causes Validation /// </summary> [Category("Appearance")] [DefaultValue(false)] [Localizable(false)] public bool CausesValidation { get { if (ViewState[ViewStateConstants.CausesValidation.ToString()] == null) { ViewState[ViewStateConstants.CausesValidation.ToString()] = false; } return (bool)ViewState[ViewStateConstants.CausesValidation.ToString()]; } set { ViewState[ViewStateConstants.CausesValidation.ToString()] = value; btnDate.CausesValidation = value; } } #endregion #region Events /// <summary> /// A day was selected from the calendar control. /// </summary> public event EventHandler SelectionChanged; protected virtual void OnSelectionChanged() { if (SelectionChanged != null) // only raise the event if someone is listening. { SelectionChanged(this, EventArgs.Empty); } } #endregion #region Event Handlers /// <summary> /// The +/- button was clicked. /// </summary> protected void btnDate_Click(object sender, System.EventArgs e) { if (!calDate.Visible) { // expand the calendar calDate.Visible = true; txtDate.Enabled = false; btnDate.Text = CollapseButtonLabel; if (DateValue != DateTime.MinValue) { calDate.SelectedDate = DateValue; calDate.VisibleDate = DateValue; } } else { // collapse the calendar calDate.Visible = false; txtDate.Enabled = true; btnDate.Text = ExpandButtonLabel; } } /// <summary> /// A date was selected from the calendar. /// </summary> protected void calDate_SelectionChanged(object sender, System.EventArgs e) { calDate.Visible = false; txtDate.Visible = true; btnDate.Text = ExpandButtonLabel; txtDate.Enabled = true; txtDate.Text = calDate.SelectedDate.ToShortDateString(); OnSelectionChanged(); } #endregion /// <summary> /// Builds the contents of this control. /// </summary> protected override void CreateChildControls() { btnDate.Text = ExpandButtonLabel; btnDate.CausesValidation = CausesValidation; txtDate.ID = "txtDate"; calDate.Visible = false; if (ApplyDefaultStyle) { calDate.BackColor = System.Drawing.Color.White; calDate.BorderColor = System.Drawing.Color.FromArgb(10066329); calDate.CellPadding = 2; calDate.DayNameFormat = DayNameFormat.Shortest; calDate.Font.Name = "Verdana"; calDate.Font.Size = FontUnit.Parse("8pt"); calDate.ForeColor = System.Drawing.Color.Black; calDate.Height = new Unit(150, UnitType.Pixel); calDate.Width = new Unit(180, UnitType.Pixel); calDate.DayHeaderStyle.BackColor = System.Drawing.Color.FromArgb(228, 228, 228); calDate.DayHeaderStyle.Font.Size = FontUnit.Parse("7pt"); calDate.TitleStyle.Font.Bold = true; calDate.WeekendDayStyle.BackColor = System.Drawing.Color.FromArgb(255, 255, 204); } ConnectEventHandlers(); pnlCalendar.Controls.Add(calDate); pnlCalendar.Style["position"] = "absolute"; pnlCalendar.Style["filter"] = "alpha(opacity=95)"; pnlCalendar.Style["-moz-opacity"] = ".95"; pnlCalendar.Style["opacity"] = ".95"; pnlCalendar.Style["z-index"] = "2"; pnlCalendar.Style["background-color"] = "White"; if (CalendarPosition == CalendarDisplay.DisplayBelow) { pnlCalendar.Style["margin-top"] = "27px"; } else { pnlCalendar.Style["display"] = "inline"; } Controls.Add(txtDate); Controls.Add(pnlCalendar); Controls.Add(btnDate); base.CreateChildControls(); } /// <summary> /// Render the contents of this control. /// </summary> /// <param name="output">The HtmlTextWriter to use.</param> protected override void RenderContents(HtmlTextWriter output) { switch (CalendarPosition) { case CalendarDisplay.DisplayRight: { txtDate.RenderControl(output); btnDate.RenderControl(output); pnlCalendar.RenderControl(output); break; } case CalendarDisplay.DisplayBelow: { pnlCalendar.RenderControl(output); txtDate.RenderControl(output); btnDate.RenderControl(output); break; } } } /// <summary> /// Connect event handlers to events. /// </summary> private void ConnectEventHandlers() { btnDate.Click += new System.EventHandler(btnDate_Click); calDate.SelectionChanged += new System.EventHandler(calDate_SelectionChanged); } } } <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" % <%@ Register Assembly="EclipseWebSolutions.DatePicker" Namespace="EclipseWebSolutions.DatePicker" TagPrefix="ews" % Untitled Page       using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void DatePicker1_SelectionChanged(object sender, EventArgs e) { Label1.Text = DatePicker1.DateValue.ToShortDateString(); pnlLabel.Update(); } }

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  • Code Golf - Banner Generation

    - by Claudiu
    When thanking someone, you don't want to just send them an e-mail saying "Thanks!", you want to have something FLASHY: Input: THANKS!! Output: TTT H H AAA N N K K SSS !!! !!! T H H A A NNN K K S !!! !!! T HHH AAA NNN KK SSS !!! !!! T H H A A N N K K S T H H A A N N K K SSS !!! !!! Write a program to generate a banner. You only have to generate upper-case A-Z along with spaces and exclamation points (what is a banner without an exclamation point?). All characters are made up of a 3x5 grid of the same character (so the S is a 3x5 grid made of S). All output should be on one row (so no newlines). Here are all the letters you need: Input: ABCDEFGHIJKL Output: AAA BBB CCC DD EEE FFF GGG H H III JJJ K K L A A B B C D D E F G H H I J K K L AAA BBB C D D EE FF G G HHH I J KK L A A B B C D D E F G G H H I J J K K L A A BBB CCC DD EEE F GGG H H III JJJ K K LLL Input: MNOPQRSTUVWX Output: M M N N OOO PPP QQQ RR SSS TTT U U V V W W X X MMM NNN O O P P Q Q R R S T U U V V W W X M M NNN O O PPP Q Q RR SSS T U U V V WWW X M M N N O O P QQQ R R S T U U V V WWW X M M N N OOO P QQQ R R SSS T UUU V WWW X X Input: YZ! Output: Y Y ZZZ !!! Y Y Z !!! YYY Z !!! Y Z YYY ZZZ !!! The winner is the shortest source code. Source code should read input from stdin, output to stdout. You can assume input will only contain [A-Z! ]. If you insult the user on incorrect input, you get a 10 character discount =P. I was going to require these exact 27 characters, but to make it more interesting, you can choose how you want them to look - whatever makes your code shorter! To prove that your letters do look like normal letters, show the output of the last three runs.

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  • Code Golf: Evaluating Mathematical Expressions

    - by Noldorin
    Challenge Here is the challenge (of my own invention, though I wouldn't be surprised if it has previously appeared elsewhere on the web). Write a function that takes a single argument that is a string representation of a simple mathematical expression and evaluates it as a floating point value. A "simple expression" may include any of the following: positive or negative decimal numbers, +, -, *, /, (, ). Expressions use (normal) infix notation. Operators should be evaluated in the order they appear, i.e. not as in BODMAS, though brackets should be correctly observed, of course. The function should return the correct result for any possible expression of this form. However, the function does not have to handle malformed expressions (i.e. ones with bad syntax). Examples of expressions: 1 + 3 / -8 = -0.5 (No BODMAS) 2*3*4*5+99 = 219 4 * (9 - 4) / (2 * 6 - 2) + 8 = 10 1 + ((123 * 3 - 69) / 100) = 4 2.45/8.5*9.27+(5*0.0023) = 2.68... Rules I anticipate some form of "cheating"/craftiness here, so please let me forewarn against it! By cheating, I refer to the use of the eval or equivalent function in dynamic languages such as JavaScript or PHP, or equally compiling and executing code on the fly. (I think my specification of "no BODMAS" has pretty much guaranteed this however.) Apart from that, there are no restrictions. I anticipate a few Regex solutions here, but it would be nice to see more than just that. Now, I'm mainly interested in a C#/.NET solution here, but any other language would be perfectly acceptable too (in particular, F# and Python for the functional/mixed approaches). I haven't yet decided whether I'm going to accept the shortest or most ingenious solution (at least for the language) as the answer, but I would welcome any form of solution in any language, except what I've just prohibited above! My Solution I've now posted my C# solution here (403 chars). Update: My new solution has beaten the old one significantly at 294 chars, with the help of a bit of lovely regex! I suspected that this will get easily beaten by some of the languages out there with lighter syntax (particularly the funcional/dynamic ones), and have been proved right, but I'd be curious if someone could beat this in C# still. Update I've seen some very crafty solutions already. Thanks to everyone who has posted one. Although I haven't tested any of them yet, I'm going to trust people and assume they at least work with all of the given examples. Just for the note, re-entrancy (i.e. thread-safety) is not a requirement for the function, though it is a bonus. Format Please post all answers in the following format for the purpose of easy comparison: Language Number of characters: ??? Fully obfuscated function: (code here) Clear/semi-obfuscated function: (code here) Any notes on the algorithm/clever shortcuts it takes.

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  • How to interpolate hue values in HSV colour space?

    - by nick
    Hi, I'm trying to interpolate between two colours in HSV colour space to produce a smooth colour gradient. I'm using a linear interpolation, eg: h = (1 - p) * h1 + p * h2 s = (1 - p) * s1 + p * s2 v = (1 - p) * v1 + p * v2 (where p is the percentage, and h1, h2, s1, s2, v1, v2 are the hue, saturation and value components of the two colours) This produces a good result for s and v but not for h. As the hue component is an angle, the calculation needs to work out the shortest distance between h1 and h2 and then do the interpolation in the right direction (either clockwise or anti-clockwise). What formula or algorithm should I use? EDIT: By following Jack's suggestions I modified my JavaScript gradient function and it works well. For anyone interested, here's what I ended up with: // create gradient from yellow to red to black with 100 steps var gradient = hsbGradient(100, [{h:0.14, s:0.5, b:1}, {h:0, s:1, b:1}, {h:0, s:1, b:0}]); function hsbGradient(steps, colours) { var parts = colours.length - 1; var gradient = new Array(steps); var gradientIndex = 0; var partSteps = Math.floor(steps / parts); var remainder = steps - (partSteps * parts); for (var col = 0; col < parts; col++) { // get colours var c1 = colours[col], c2 = colours[col + 1]; // determine clockwise and counter-clockwise distance between hues var distCCW = (c1.h >= c2.h) ? c1.h - c2.h : 1 + c1.h - c2.h; distCW = (c1.h >= c2.h) ? 1 + c2.h - c1.h : c2.h - c1.h; // ensure we get the right number of steps by adding remainder to final part if (col == parts - 1) partSteps += remainder; // make gradient for this part for (var step = 0; step < partSteps; step ++) { var p = step / partSteps; // interpolate h var h = (distCW <= distCCW) ? c1.h + (distCW * p) : c1.h - (distCCW * p); if (h < 0) h = 1 + h; if (h > 1) h = h - 1; // interpolate s, b var s = (1 - p) * c1.s + p * c2.s; var b = (1 - p) * c1.b + p * c2.b; // add to gradient array gradient[gradientIndex] = {h:h, s:s, b:b}; gradientIndex ++; } } return gradient; }

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  • Why do some questions get closed for no reason? [closed]

    - by IVlad
    Recently there was a question asking about generating all subsets of a set using a stack and a queue, which was closed (and now deleted it seems) as not a real question for no good reason, since it didn't fit into any of these conditions: It's difficult to tell what is being asked here. No, it was clear what was being asked. This question is ambiguous, vague, incomplete, or rhetorical and cannot be reasonably answered in its current form. Not ambiguous, not vague, not incomplete, definitely not rhetorical and could easily be answered if one knew the solution. Now, the exact same thing has happened with this question: http://stackoverflow.com/questions/2791982/a-shortest-path-problem-with-superheroes-and-intergalactic-journeys/2793746#2793746 I am interested in hearing a logical argument for why that question is either ambiguous, vague, incomplete, rhetorical or cannot reasonably be answered in its current form. It seems that (the same bunch of) people like to close questions that they think are homework questions, especially when they think people want to be served the solution on a platter, which is also not the case: Any suggestions or ideas of how this problem might be solved would be most welcomed. Most of the time the people asking these questions are very reasonable and appreciate even the most vague idea, yet their question is closed. Let's go further and assume that it IS a homework problem. So what? When I registered here I didn't see any rule that said not to post homework problems, nor do I see such a rule now. What is wrong with posting homework problems that makes people hunt them down with a passion to close them without even reading the entire question body? This site is full of questions asked by people who get paid to know the things they are asking, yet their questions are considered fine. How is solving someone's homework problem worse? In some places (like where I live), computer science is a mandatory high school subject, and not everyone is interested in it. How is helping at least those people worse than doing someone's JOB? Not answering homework questions is fine and it's everyone's choice, but I consider closing them to be an act of power abuse, selfishness, and an insult to the fellow community members who are also interested in a solution or want feedback on their proposed solution. So my questions are: - Why do questions like the above get closed for reasons that do not apply? Why do you close them? Why don't you? - Why doesn't a vote to reopen a question reopen it automatically? Needing 5 votes for a reopen takes too long, and it's not fair because one reopen vote basically cancels out a close vote, making it 4 close votes (or 5 to 1, which is the same as only 4 people wanting to close the question), which isn't enough to close the question. I think a question should only be closed when CloseVotes - ReopenVotes >= 5. I'm hoping this will stay up, but I realize it probably won't. In either case, I think this is worth saying and discussing, since it IS community-related.

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  • Code-Golf: Friendly Number Abbreviator

    - by David Murdoch
    Based on this question: Is there a way to round numbers into a friendly format? THE CHALLENGE - UPDATED! (removed hundreds abbreviation from spec) The shortest code by character count that will abbreviate an integer (no decimals). Code should include the full program. Relevant range is from 0 - 9,223,372,036,854,775,807 (the upper limit for signed 64 bit integer). The number of decimal places for abbreviation will be positive. You will not need to calculate the following: 920535 abbreviated -1 place (which would be something like 0.920535M). Numbers in the tens and hundreds place (0-999) should never be abbreviated (the abbreviation for the number 57 to 1+ decimal places is 5.7dk - it is unneccessary and not friendly). Remember to round half away from zero (23.5 gets rounded to 24). Banker's rounding is verboten. Here are the relevant number abbreviations: h = hundred (102) k = thousand (103) M = million (106) G = billion (109) T = trillion (1012) P = quadrillion (1015) E = quintillion (1018) SAMPLE INPUTS/OUTPUTS (inputs can be passed as separate arguments): First argument will be the integer to abbreviate. The second is the number of decimal places. 12 1 => 12 // tens and hundreds places are never rounded 1500 2 => 1.5k 1500 0 => 2k // look, ma! I round UP at .5 0 2 => 0 1234 0 => 1k 34567 2 => 34.57k 918395 1 => 918.4k 2134124 2 => 2.13M 47475782130 2 => 47.48G 9223372036854775807 3 => 9.223E // ect... . . . Original answer from related question (javascript, does not follow spec): function abbrNum(number, decPlaces) { // 2 decimal places => 100, 3 => 1000, etc decPlaces = Math.pow(10,decPlaces); // Enumerate number abbreviations var abbrev = [ "k", "m", "b", "t" ]; // Go through the array backwards, so we do the largest first for (var i=abbrev.length-1; i>=0; i--) { // Convert array index to "1000", "1000000", etc var size = Math.pow(10,(i+1)*3); // If the number is bigger or equal do the abbreviation if(size <= number) { // Here, we multiply by decPlaces, round, and then divide by decPlaces. // This gives us nice rounding to a particular decimal place. number = Math.round(number*decPlaces/size)/decPlaces; // Add the letter for the abbreviation number += abbrev[i]; // We are done... stop break; } } return number; }

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  • Problem on a Floyd-Warshall implementation using c++

    - by Henrique
    I've got a assignment for my college, already implemented Dijkstra and Bellman-Ford sucessfully, but i'm on trouble on this one. Everything looks fine, but it's not giving me the correct answer. Here's the code: void FloydWarshall() { //Also assume that n is the number of vertices and edgeCost(i,i) = 0 int path[500][500]; /* A 2-dimensional matrix. At each step in the algorithm, path[i][j] is the shortest path from i to j using intermediate vertices (1..k-1). Each path[i][j] is initialized to edgeCost(i,j) or infinity if there is no edge between i and j. */ for(int i = 0 ; i <= nvertices ; i++) for(int j = 0 ; j <= nvertices ; j++) path[i][j] = INFINITY; for(int j = 0 ; j < narestas ; j++) //narestas = number of edges { path[arestas[j]->v1][arestas[j]->v2] = arestas[j]->peso; //peso = weight of the edge (aresta = edge) path[arestas[j]->v2][arestas[j]->v1] = arestas[j]->peso; } for(int i = 0 ; i <= nvertices ; i++) //path(i, i) = 0 path[i][i] = 0; //test print, it's working fine //printf("\n\n\nResultado FloydWarshall:\n"); //for(int i = 1 ; i <= nvertices ; i++) // printf("distancia ao vertice %d: %d\n", i, path[1][i]); //heres the problem, it messes up, and even a edge who costs 4, and the minimum is 4, it prints 2. //for k = 1 to n for(int k = 1 ; k <= nvertices ; k++) //for i = 1 to n for(int i = 1 ; i <= nvertices ; i++) //for j := 1 to n for(int j = 1 ; j <= nvertices ; j++) if(path[i][j] > path[i][k] + path[k][j]) path[i][j] = path[i][k] + path[k][j]; printf("\n\n\nResultado FloydWarshall:\n"); for(int i = 1 ; i <= nvertices ; i++) printf("distancia ao vertice %d: %d\n", i, path[1][i]); } im using this graph example i've made: 6 7 1 2 4 1 5 1 2 3 1 2 5 2 5 6 3 6 4 6 3 4 2 means we have 6 vertices (1 to 6), and 7 edges (1,2) with weight 4... etc.. If anyone need more info, i'm up to giving it, just tired of looking at this code and not finding an error.

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  • Abnormally disconnected TCP sockets and write timeout

    - by James
    Hello I will try to explain the problem in shortest possible words. I am using c++ builder 2010. I am using TIdTCPServer and sending voice packets to a list of connected clients. Everything works ok untill any client is disconnected abnormally, For example power failure etc. I can reproduce similar disconnect by cutting the ethernet connection of a connected client. So now we have a disconnected socket but as you know it is not yet detected at server side so server will continue to try to send data to that client too. But when server try to write data to that disconnected client ...... Write() or WriteLn() HANGS there in trying to write, It is like it is wating for somekind of Write timeout. This hangs the hole packet distribution process as a result creating a lag in data transmission to all other clients. After few seconds "Socket Connection Closed" Exception is raised and data flow continues. Here is the code try { EnterCriticalSection(&SlotListenersCriticalSection); for(int i=0;i<SlotListeners->Count;i++) { try { //Here the process will HANG for several seconds on a disconnected socket ((TIdContext*) SlotListeners->Objects[i])->Connection->IOHandler->WriteLn("Some DATA"); }catch(Exception &e) { SlotListeners->Delete(i); } } }__finally { LeaveCriticalSection(&SlotListenersCriticalSection); } Ok i already have a keep alive mechanism which disconnect the socket after n seconds of inactivity. But as you can imagine, still this mechnism cant sync exactly with this braodcasting loop because this braodcasting loop is running almost all the time. So is there any Write timeouts i can specify may be through iohandler or something ? I have seen many many threads about "Detecting disconnected tcp socket" but my problem is little different, i need to avoid that hangup for few seconds during the write attempt. So is there any solution ? Or should i consider using some different mechanism for such data broadcasting for example the broadcasting loop put the data packet in some kind of FIFO buffer and client threads continuously check for available data and pick and deliver it to themselves ? This way if one thread hangs it will not stop/delay the over all distribution thread. Any ideas please ? Thanks for your time and help. Regards Jams

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  • Code Golf: Countdown Number Game

    - by Noldorin
    Challenge Here is the task, inspired by the well-known British TV game show Countdown. The challenge should be pretty clear even without any knowledge of the game, but feel free to ask for clarifications. And if you fancy seeing a clip of this game in action, check out this YouTube clip. It features the wonderful late Richard Whitely in 1997. You are given 6 numbers, chosen at random from the set {1, 2, 3, 4, 5, 6, 8, 9, 10, 25, 50, 75, 100}, and a random target number between 100 and 999. The aim is to make use the six given numbers and the four common arithmetic operations (addition, subtraction, multiplication, division; all over the rational numbers) to generate the target - or as close as possible either side. Each number may only be used once at most, while each arithmetic operator may be used any number of times (including zero.) Note that it does not matter how many numbers are used. Write a function that takes the target number and set of 6 numbers (can be represented as list/collection/array/sequence) and returns the solution in any standard numerical notation (e.g. infix, prefix, postfix). The function must always return the closest-possible result to the target, and must run in at most 1 minute on a standard PC. Note that in the case where more than one solution exists, any single solution is sufficient. Examples: {50, 100, 4, 2, 2, 4}, target 203 e.g. 100 * 2 + 2 + (4 / 4) e.g. (100 + 50) * 4 * 2 / (4 + 2) {25, 4, 9, 2, 3, 10}, target 465 e.g. (25 + 10 - 4) * (9 * 2 - 3) {9, 8, 10, 5, 9, 7), target 241 e.g. ((10 + 9) * 9 * 7) + 8) / 5 Rules Other than mentioned in the problem statement, there are no further restrictions. You may write the function in any standard language (standard I/O is not necessary). The aim as always is to solve the task with the smallest number of characters of code. Saying that, I may not simply accept the answer with the shortest code. I'll also be looking at elegance of the code and time complexity of the algorithm! My Solution I'm attempting an F# solution when I find the free time - will post it here when I have something! Format Please post all answers in the following format for the purpose of easy comparison: Language Number of characters: ??? Fully obfuscated function: (code here) Clear (ideally commented) function: (code here) Any notes on the algorithm/clever shortcuts it takes.

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