ahmed_aly's blog

Codeforces Practice Ladders — A2 Online Judge
By ahmed_aly, 6 years ago, In English

Recently I added a new feature in A2 Online Judge, it's called Practice Ladders. A practice ladder is just a list of problems, and you can add some dependencies between the problem (for example, you must solve problem X before being able to see problem Y). Also you can add dependencies between the ladders and each other (for example, you must solve all problems in ladder X before being able to see any problem in ladder Y).

Also I created 7 Codeforces practice ladders which should you to increase your level, each ladder contains 100 Codeforces problems. Find which ladder is appropriate for you and enjoy!

Div. 2 A Problems: http://a2oj.com/Ladder.jsp?ID=4

Div. 2 B Problems: http://a2oj.com/Ladder.jsp?ID=5

Div. 2 C Problems: http://a2oj.com/Ladder.jsp?ID=6

Div. 2 D Problems: http://a2oj.com/Ladder.jsp?ID=7

Div. 2 E Problems: http://a2oj.com/Ladder.jsp?ID=8

Div. 1 D Problems: http://a2oj.com/Ladder.jsp?ID=9

Div. 1 E Problems: http://a2oj.com/Ladder.jsp?ID=10

 
 
 
 
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Comments Comments (90)
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6 years ago, # |
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Wonderful . Thank you very much Ahmed Ali Brother.

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6 years ago, # |
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its really nice addition to a2oj

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6 years ago, # |
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Can I solved Div. 2 A Problems directly before the practice ladders id 1,2,3 ?

I tried to solve practice ladders id 4 , but I am not getting where I have to submit the solution?

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    6 years ago, # ^ |
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    To solve problems from any ladder, you have to just go to the problem link, which will direct you to the actual problem link on Codeforces. You, then solve the problem as usual and after getting it accepted, go to your profile on A2oj and update Codeforces profile there, next problem will be automatically unlocked in the same ladder.

    Hope this helps.

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      6 years ago, # ^ |
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      Thanks for the reply. I have tried the same but I am not able to update my A2oj profile. Actually the first problem was already submitted before so I submit it again but it does not count it solved.

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      4 years ago, # ^ |
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      can u help me in this:

      1. Magdy

      Problem Statement: Magdy is a high school student who wants to join the EOI and IOI to get a scholarship in MIT. MIT is in the USA and it Ranked number one in engineering. Magdy must solve at least one problem everyday in the EOI ladder to achieve his goal. Write a program to encourage Magdy to work harder to get a scholarship.

      Input Format: single integer represent the number of problems Magdy solved today

      Output Format: if the number of problem solved is less than one print "Don't be lazy, it takes only few minutes, you can do it." if the number of problem solved is one print "Good Job" if the number of problem solved is more than one "You Rocks Man"

      Sample Input: 1

      Sample Output: Good Job

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6 years ago, # |
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Hello, the idea is awesome, thanks! Can you check the Div2 D's ladder second problem, please? Actually, it is a Div2 B problem, not D, and I got AC twice and it doesn't count it as solved.

PS: I have clicked the update button.

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6 years ago, # |
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This feature is very nice, interesting and also motivational. I think this feature helps me to select the problems for practise. Thank you ahmed_aly

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6 years ago, # |
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Thanks... That's a great feature.
I think it makes better, If people can filter or change the priority of problems in a ladders for themselves.

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6 years ago, # |
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How about ladder for SPOJ? It has a very good collection of problems, but it is a mess. Could you please add that feature? It will be very helpful. :)

By the way, thank you very much for this wonderful feature.

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6 years ago, # |
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Thank you for this wonderful feature. I have one request, once I complete a ladder the ladder should be highlighted in green (similar to accepted problem) on the ladders page.

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6 years ago, # |
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Great Work :)

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6 years ago, # |
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Hello ahmed_aly,

It is taking too much time to update the problem that you have solved in the list. Can there be some improvement ?

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6 years ago, # |
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Is the judge currently down ? presently I am unable to access.
UPD : It's working now :)

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6 years ago, # |
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The system a2oj is down again!!!

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    6 years ago, # ^ |
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    It should be back now. Sorry for any inconvenience.

    -- Ahmed Aly

    www.a2oj.com

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6 years ago, # |
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Thanks a lot this offers us (beginners) much help !

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6 years ago, # |
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Now nobody can login on the system!!!

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6 years ago, # |
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why I have to log in after every 15 minute ? it keeps me continuously logged out from a2oj.com after every 15 minute though I checked the Remember me checkbox .

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6 years ago, # |
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I am getting HTTP Status 500 — java.lang.NullPointerException in Div2 D ladder.

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6 years ago, # |
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Its showing me This username doesn't exist O.o

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5 years ago, # |
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i have a problem when i solved the first time to solve problems and they are all accepted but when i try to solve the Little Experience problems the website make me go to first time to solve again ?? any help please ??

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5 years ago, # |
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Sorry, but the ladder does not work. When I updated, the red text saying " Your solved problems for this ladder will be updated within few minutes ", and the next problem is hidden. Waited a few days, no changes.

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    5 years ago, # ^ |
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    Did you updated your codeforces handle under "My Account" on A2 site and then updated the solved problems list on the ladder page ?

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5 years ago, # |
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Is there's some problem with a2oj.com right now?

it keep telling me that username doesn't exist!!!

is it only me?

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5 years ago, # |
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is a2oj down right now when will it get fixed???

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5 years ago, # |
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Any update on when a2oj is coming back??

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    5 years ago, # ^ |
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    A2 Online Judge is back. I'm really sorry for the delay.

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5 years ago, # |
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when a2oj will be back again ??? any update ????

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    5 years ago, # ^ |
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    A2 Online Judge is back. I'm really sorry for the delay.

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      5 years ago, # ^ |
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      it still doesn't update SPOJ, Timus problem list.

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5 years ago, # |
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I think it just did come up!!

let's hope it will keep it up :D :D !!

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5 years ago, # |
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Hi ahmed_aly, do these list contain random 100 problems or according to some order?

Like does the Div2 C ladder has 100 random Div2 C questions or are they in some order?

Thanks

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5 years ago, # |
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ahmed_aly Can i save pages of A2OJ on Internet Archive, so that if it goes down we can reuse the saved pages from Internet Archive ???

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5 years ago, # |
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A2OJ isn't updating my solved problems for Codeforces. :( Please fix the bug.

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    5 years ago, # ^ |
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    Did you change your handle?? If so you have to update it in the website also.

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      5 years ago, # ^ |
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      oh !! thanks a lot !! i forgot that !!

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5 years ago, # |
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My codeforces handle is "newcoder_69" but A2OJ says that my handle does not exist, I tried multiple times. :/

Please help me.

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5 years ago, # |
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ahmed_aly I'm sorry to bother, it's just that my A2OJ account is signing me in with another account. First everything works fine, but when I click on My Account it changes my account to another account, can you help me with this?

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5 years ago, # |
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is site down right now ?? or i am the only one facing the problem ??

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    5 years ago, # ^ |
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    seems like the site is down. i can't access too. :(

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    5 years ago, # ^ |
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    It's back now. Sorry I made a mistake yesterday just before sleeping while fixing some stuff.

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5 years ago, # |
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Hi, when I go to "My Account" and try to add my SPOJ account it always says "This is invalid SPOJ username", can you fix that? My accounts for a2oj and spoj are both Secta if you need this info :)

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    5 years ago, # ^ |
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    Secta doesn't exist.

    Probably you mean secta? It's case sensitive.

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      5 years ago, # ^ |
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      Thank you and sorry :)

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      3 years ago, # ^ |
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      Hi, ahmed_aly , I have a similar problem. When I go to "My Account" and try to add my SPOJ account, it says "This is invalid SPOJ username".

      My username is pravad for both spoj and a2oj, and I didn't make a mistake in the case for sure.

      Can you please help? Thanks!

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        2 years ago, # ^ |
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        i have the same problem

        spoj username: jabal97_ov

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        2 years ago, # ^ |
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        Same here. SPOJ username: menna_mohie

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        2 years ago, # ^ |
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        Same here. A2OJ username: Sir_Edward. SPOJ username: sir_edward.

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        2 years ago, # ^ |
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        I have the same problem, my spoj username is mshafquat, and I didn't make any mistakes. Still it is invalid!

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        2 years ago, # ^ |
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        Same here. A2OJ username: NexMickey. SPOJ username: nexmickey

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4 years ago, # |
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I am not able to use it.Can some one say me how to use because I have updated my account there and so it is showing only the first question.

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    4 years ago, # ^ |
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    you must solve first problem to show the second and solve the second to show third...... or you mean that you solve it and now it is unavailable ???

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4 years ago, # |
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A2OJ is down ... When will it be back ??

it will be very helpful if anyone could provide me with problems in each ladder if there is still much time before working again.

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4 years ago, # |
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Why the site is not working? It is down and when it will be working?

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4 years ago, # |
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If anybody has a screen-shot of the DIV2D ladder problems , please share it as the site is down.

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4 years ago, # |
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I started doing Div C (ladder Id=6) yesterday and completed the first question but still the second question is hidden!! I have tried clicking on the "Update" button,it says it will take a few minutes but still it isnt getting updated. Can you please help.

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    4 years ago, # ^ |
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    Does you link your codeforces handle with A2OJ?

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      4 years ago, # ^ |
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      how to link my handle to A2Oj?

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        4 years ago, # ^ |
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        On the top of the site next to your username click on "My Account". Then scroll down and find a field named "Codeforces Handle" write your handle there. Don't forget to update your data :)

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4 years ago, # |
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Superb work Ahmed Sir !!

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4 years ago, # |
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the ladder do not count the problem that I solve anymore that happened at the problem 24 so I can not go any more for a new problems note : my data at "a2oj" site is right... what should I do ???

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    4 years ago, # ^ |
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    Thats because codeforces api is not available at the moment for VK cup finals. It should be available shortly and then a2oj can also update the data.

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3 years ago, # |
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Is the server down.I updated my problem and it is showing me "Your solved problem for this ladder will be updated within few minutes" and it's been quite long .What to do ? P.S. Thanks in advance!

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18 months ago, # |
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Extremely helpful. Thanks a lot G!

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    17 months ago, # ^ |
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    the site is nearly always down

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      17 months ago, # ^ |
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      Yeah true... The site is almost always down these days... Which wasn't the case a few weeks back...

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13 months ago, # |
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Great work. But the ladder take so long to update. Would anyone please provide me screenshot of their solved ladder C (div2) so that i can personally solve all ladder problems without waiting.

That would be great. Thanks in advance https://a2oj.com/ladder?ID=6 @ahmed_aly

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12 months ago, # |
← Rev. 2   Vote: I like it -19 Vote: I do not like it

.

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7 months ago, # |
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It takes too long to update on a2oj ladders. I've solved Div2D problem 1 and now it's been almost 25 mins and still it has not updated it. Please resolve this issue ASAP.

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6 months ago, # |
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Why A2 online judge website is showing error. It is a useful website for beginners. Please fix it

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6 months ago, # |
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Can we get static ladders back?

Found : https://codeforcesladders.firebaseapp.com/

If anyone is interested in ladders may use it.

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    6 months ago, # ^ |
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    Thank you kind stranger... I really wanted this!

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    6 months ago, # ^ |
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    thank you my dude.. very helping.. here, take my upvote..

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6 months ago, # |
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a2oj is down as of the time I am writing this comment. It used to be a great resource ;(

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6 months ago, # |
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Are there any particular timings in which A2oj will be working?

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40 hours ago, # |
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I can't see my solved problems marked as green on a2oj. They are not getting updated as earlier, any suggestions?

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