uhunt.onlinejudge.org Open in urlscan Pro
51.158.37.101  Public Scan

Form analysis
4 forms found in the DOM

POST

<form autocomplete="on" ng-submit="sign_in()" method="POST" class="ng-pristine ng-valid">
  <table align="center" style="border:1px dotted #6666FF; padding:0 15px 0 15px" cellspacing="5">
    <tbody>
      <tr>
        <td><input type="checkbox" ng-click="toggle_invisible()" ng-checked="is_invisible"> Invisible</td>
        <td align="right">
          <input type="submit" value="Sign In" ng-disabled="logging_in">
          <input type="button" ng-click="show_login_dialog=false" value="Cancel">
        </td>
      </tr>
    </tbody>
  </table>
</form>

<form ng-submit="post_message()" ng-disabled="post_chat_disabled" class="ng-pristine ng-valid">
  <input type="text" ng-disabled="post_chat_disabled" ng-model="post_text" placeholder="post your message here (max 255 chars)" style="height:18px; width:405px; outline:none;" class="ng-pristine ng-valid">
</form>

<form style="margin:0" onsubmit="return view_username();" class="ng-pristine ng-valid">
  <p style="margin:0">Your UVa username : <input id="u_input" name="u" type="text" placeholder="UVa username" value="" size="15">
    <input type="submit" value="Submit">
  </p>
</form>

<form ng-submit="show_search_result=true; search()" class="ng-pristine ng-valid">
  <p>Search Problem Number : <input ng-model="search_number" value="100" style="width:75px" class="ng-pristine ng-valid">&nbsp; <input type="submit" value="Search">
    <button ng-click="search_number=''; hide()">Clear</button>
  </p>
</form>

Text Content

-- Users(0/25):11M

Peter> hi
Peter> ko
Peter> Anyone from India ?
satya576> yes. fro India
--- ? ---> Indian
Peter> Hi. I am new to uva. how can i find editorial of problems like they are
in other OJs?
Peter> hi
hhammoud> hello
hhammoud> anyone here ?
tomeslav> hi Peter
tomeslav> UVA has no editorials, it's old school archive style
tomeslav> you can find solutions in github or forums
tomeslav> blogposts, wikipedia...
rocketchicken> hay there
yiman_a> uva is so slow
nibras2002> Hello
nibras2002> Is this global chat?
nibras2002> pretty cool
nibras2002> I like how it shows live submissions
nibras2002> Makes me feel I want to solve more problems
gods_hand> thanks @tomeslav
normatov_d> hey
R10945053> Guys! Please do not pollute server with submissions. Submit one -
wait for response - submit another. Please do not submit several cases at once.
Thanks!
seebe> can someone help me with a dp problem ?
tommy_trash> Can someone help me with 259 (r|d), oj takes ac with edge weight 1
but cp3 says to take inf. Don't know why inf is suggested ?
nibras2002> Yo
pydithalli> where can we check our rankings?
ThePeeps191> hello kids
Robber> hi
Robber> why uva was sometimes out of services?
Serious Noob> don't know, must be one of the mysteries of the universe
tomeslav> I'd very much like to know why UVA doesn't update its C++ compiler
version
vipboy0402hcm> Just solving starred problems is enough or I have to do all ?
ncc02> @vipboy0402hcm If you have solved lv4, lv5,.. I think there's no need to
solve more problems
neuronz> 821 (r|d)
Taalpatar_Shepai> Hi
Taalpatar_Shepai> UVA should update their Website.
Taalpatar_Shepai> Like LightOJ did.
arafat666> is there any alternative of the icpc live archive problemset? The
main site is down
metaphysis> How can I contact the adminstrator of Online Judge?
rene.argento> I wish I knew too. Some questions have broken I/O for years now..
metaphysis> Hi, rene.argento, I check the list of solved problems, found that
you have solved the 11627 (r|d) by Java, I tried to solve it by C++ but failed.
Can you give me some tips?
metaphysis> It seems that there are some bugs in judge data of problem 11627
(r|d).
rene.argento> Yes, that is one of the problems for which the I/O is broken. Took
me 46 submissions but I found a work-around.. I can send you the details of what
I did. Do you have an e-mail or some social media account I can write to?
metaphysis> My email is metaphysis@yeah.net, thank you!
rene.argento> Cool, I sent you all the details there
metaphysis> thank you, I got AC finally. I check the accepted submission by UVA
Arean.
metaphysis> the details is in email
rene.argento> Great, thanks! Hopefully we will find a solution to UVa-12348 and
UVa-431 someday :)
SpamBot> Is there an IO guide or something?
SpamBot> UVa really needs an upgrade
SpamBot> N
SpamBot> I
SpamBot> G
SpamBot> E
SpamBot> R
yiman_a> SpamBot, fuck youy
Peter> 123 (r|d)
raizz> 2
Jubair_7> hii
k124k3n> shalom
kennyarlexy> shalom
k124k3n> :'(
HeNeos> pipipi
codedguy> hello coders
Peter> hgjh
Peter> dfsf
gods_hand> hi
grazier> hello, i need a problem list for square root decomposition and MO
algorithm, can you help me?
aam.oj> Square Root Decomposition Problem List:
https://codeforces.com/blog/entry/23005
aam.oj> MO's Algorithm:
https://www.scaler.com/topics/data-structures/mos-algorithm/
Solitude> Hello everyone, can anybody help me with 11182 (r|d)-Zeros lll
problem? With all the provided input in udebug as well as online judge forum
gave me correct output but got WA 3 times
raiky_sahb> hi
grazier> thanks you
aam.oj> Guys, what does "Lev N" mean in uHunt?
SpamBot> My guess it's assumed problem difficulty level
rene.argento> @Miguel Revilla nice to see you around here. Any plans to fix the
I/O of some problems that are broken such as UVa-12348 and UVa-431?
aam.oj> Thanks @SpamBot.
Serious Noob> How to see/find out problem level??
k124k3n> sleep
Fysics> ?
kabid241> প্রিয় সুধী, পরম করুণাময় ও অসীম দয়ালু মহান আল্লাহ তা'আলার অশেষ রহমতে
আগামী ১০ মার্চ রোজ শুক্রবার আমার বন্ধু সামিউল ইসলাম মুগ্ধ এর বড় বোনের শুভ বিবাহ
অনুষ্ঠিত হইবে। আপনারা সপরিবারে আমন্ত্রতিত। প্রীতিভোজঃ বাদ জুমাহ দুপুর ২ টা ।
বিদ্রঃ দোয়া ও উপহার উভয়ই কাম্য
nayeem2021> @Kabid241 ঠিকানা দেন ভাই।
Luis_XIV> manoel mama
Luis_XIV> luig0
kabid241> .
kabid241> ..
dionxj8> oj died?
Luis_XIV> MANOEL MAMA MUITO
Peter> Why so long judge queue???
Peter> Tell me why Ain't nothin' but a heartache Tell me why Ain't nothin' but a
mistake Tell me why I never wanna hear you say I want it that way
Peter> btw can anyone explain Problem 624 (r|d).
Peter> I cannot even understand the statement.
Peter> You have a long drive by car ahead. You have a tape recorder, but
unfortunately your best music is on CDs. You need to have it on tapes so the
problem to solve is: you have a tape N minutes long. How to choose tracks from
CD to get most out of
lumid> hi
SpamBot> Problem 624 (r|d) seems like a typical knapsack dp
SpamBot> Also links are fucking buck broken
SpamBot>
https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=565
jessuar_Hoyos> Holo
Gadiel Solís> .

You are signed in as .
you are currently invisible

Sign Out Close

To sign in, please login to the UVa Online Judge site.

If you have done so, click the sign in button below.

Invisible

[ Sign In ]


uHunt
hunt problems that matter


uHunt is a tool for UVa online-judge that keeps statistics, provide selections
of problems to solve, and exposes a web API for other web developers to build
upon it.

To quickly submit your solution, use UVa Quick Submit.


Your UVa username :

Search Problem Number :   Clear


-   [ STATISTICS / DISCUSS]   (HIDE)



View : [ last | yours(0) ]     Show : [ 5 | 10 | 50 | 100 | 500   Submissions  
# Rank   User (username)   Verdict Lang Time Submit Time

View : [ the-top | nearby ]     Show : [ 5 | 10 | 50 | 100 | 500   Ranklist   #
Rank   User (username) Lang Time Submit Time

--------------------------------------------------------------------------------


Show : 5 | 10 | 25 | 50 | 100   Live Submissions (hide)     #   Problem Title  
User (username)   Verdict Lang Time Best Rank Submit Time  29227765 11057
discuss Exact Sum 关云长 (vjudge1)  Wrong answer C++11 0.010 0.000 - 1 mins ago
 29227764 11857 discuss Driving Range 马孟起 (vjudge4)  Time limit C++11 5.000
0.040 - 1 mins ago  29227763 11175 discuss From D to E and Back 马化腾 (vjudge6)
 Accepted C++11 0.320 0.010 264 1 mins ago  29227762 818 discuss Cutting Chains
kxb75 (kxb75)  Wrong answer C++11 0.150 0.000 - 2 mins ago  29227761 10986
discuss Sending email 马孟起 (vjudge4)  Accepted C++11 0.280 0.010 4988 2 mins ago

View Live Submissions



--------------------------------------------------------------------------------


WHAT IS UHUNT

uHunt is my personal (self-financed) project. It is a tool that helps me (and
others) to find interesting algorithm problems to solve at UVa Online Judge as
well as keeping statistics of the currently solved problems. uHunt also exposes
web API for other web developers that are interested in querying UVa submissions
data and build their own tools.


HOW UHUNT WAS INVENTED

I love solving programming contest (algorithm) problems. Back at year 2000, the
only authoritative Online Judge that hosts good quality of past programming
contest problems was the UVa Online Judge. However, as a newbie at that time, I
was confused and frustrated in picking the next problem to solve. I want the
next problem to match my current skill (i.e, not too hard). That was what
triggered me to build a tool (a website) to organize the problems according to
the difficulty level. At that time I only use the tool for myself, but over
time, people around the world began to recognize the website and started using
it.


HOW UHUNT EVOLVED OVER TIME (DEVELOPMENT CHALLENGES)

I keep using the tool myself and improve it bit by bit whenever I have spare
time. Along the way, I learned a few web programming technologies like HTML,
Javascript, PHP, MySQL. However, as the number of concurrent users accessing the
website grows to more than 100 per day, the (shared) server began to crumble.
This is because the tool requires high interactivity. It tries to display the
most up-to-date statistics and provide chat functionality for small discussions.
The Apache web server was not good enough to handle such workload. Fortunately,
a new platform emerged (node.js) that solved the c10k problem which allows a
regular server to handle thousands of concurrent clients with far smaller memory
footprint. This was the perfect platform to switch to. Building uHunt as a
node.js application was easy as it uses Javascript which I'm familiar about.
However, there was another problem, the database (MySQL) was also beginning to
crumble as the number of rows in the submission table went close to 10 millions
(UVa OJ has that many submissions and growing). The time to update/maintain the
indexes is so high that it increases the latency (responsiveness) of the
website. I began to search for new database technology and stumbled upon a new
exciting adaptive indexing technology called Database Cracking. It was perfect
for my needs as it can process a large amount of tuples with low latency for
each individual query. Moreover, it quickly gets faster (adapt) as more queries
are performed! I built my own version of the Database Cracking using C++ and
connect it to my node.js application. Since then, uHunt has been running fast
and attracting even more users (reaching 200+ concurrent users per day). Thanks
to the UVa admin for granting uHunt a direct database access which allows uHunt
to have a timely response to user submissions. With these powerful technologies,
it does scale well and allows me to expose uHunt as a web API for other tools to
build upon. The web API is like a JSON data feed that can be used by other web
developers who are interested in building variety of other tools for UVa OJ such
as virtual contests, custom ranklists, or any other statistical tools.


WHO HAS BEEN USING UHUNT

uHunt has been heavily used by the National University of Singapore to train
computer science students for ACM ICPC. The popularity of uHunt increases even
more when universities around the world included uHunt and the Competitive
Programming book in their list of references. The book exercises are integrated
with uHunt for self-training.

It has been an amazing experience to see uHunt grows :)






--------------------------------------------------------------------------------

© Felix Halim 2016