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Challenges | Reply
Hi,

I couldn't find the rules or announcements about this new challenge rule: "you must have positive score to challenge..". :'|

I wanted to hack a solution and I have failed to generate a proper test case, then my score went to -25 (not sure if my 250 was challenge before or after that). Then I could not try again.. latter on someone else challenged that code. There were other wrong codes that I wished to challenge, but the system wouldn't allow me. What is the purpose of this restriction?

Thanks.
Re: Challenges (response to post by brunoja) | Reply
It's not a new rule (it's been in place for as long as I've been here). For the exact rule, refer here and see section 6.2: "You may only submit a challenge if you have a score of zero or greater at the time of the challenge. Once your score drops below zero, you will no longer have the option / ability to challenge."

As for the reasons, I'm not totally sure but it may have been done to help stabilize rating diving. For example, someone may perform poorly in Div I on purpose to go back to Div 2 if they know a money match is coming soon. Several years ago, there used to be many money matches, so it was advantageous to be in Div 2 for those since it would be easier to win a room than in Div I. People placing in top 2 or 3 positions in a room usually won the money in those money matches.

Anyway, for an ancient forum discussion on this topic, you can refer here. Note that other rules were different back then, so a lot of the info is outdated.
Re: Challenges (response to post by brunoja) | Reply
Lol, what a ridiculous rule. Another reason not to like TopCoder :P.

If someone wants to take very low position, then he should send incorrect codes to all problems gaining many points, do as many challenges as he can (his actual amount of points can be decreased, because someone may challenge his obviously incorrect code) and then lose many points on challenge phase, what will result in score approximately -1500 or something without much effort.
Re: Challenges (response to post by Swistakk) | Reply
I agree that the rule is a bit archaic. If someone truly wants to dive, he can do so by getting negative points already. And with next to none money matches, there's not much purpose in doing so either.
Re: Challenges (response to post by ffao) | Reply
I don't agree with that, if the rule wasn't applied, someone, who doesn't care about rating could easily generate 100 test cases and blindly challenge all submission in the room, the result would be that (s)he would have -1500 points, probably challenged most of wrong submissions and nobody else would have any chance to gain some points, that would mean disadvantage for all other contestants in that room and thus ruin the challenge phase
Re: Challenges (response to post by bohuss) | Reply
If you want to prevent that, just put a more reasonable limit on scoring, something like -100 or -150.
Re: Challenges (response to post by bohuss) | Reply
@bohuss: On Codeforces there is no such rule and nobody ever faced that issue. How do you imagine generating 100 tests for all solutions? This would have to be handled by some solid software, surely not by a human.
Re: Challenges (response to post by brunoja) | Reply
I like the rule, I would even like it to be improved so that you need a non-challenged submission on that problem before attempting challenging. Let people earn the right to challenge.
Re: Challenges (response to post by vexorian) | Reply
That makes the challenging system more asymmetric than it already is. You would give an unfair advantage to whoever submits a wrong solution and does not get challenged as opposed to someone that submits a wrong solution and gets challenged quickly.
Re: Challenges (response to post by ffao) | Reply
That would be more motivation for the other people who submitted a solution to challenge.
Re: Challenges (response to post by vexorian) | Reply
@vexorian: What about NO?

In CF solutions has to pass at least pretests to be treated as "claimed to be solved", on TC you can submit Hello world! and still get pts for some time. ffao got good point.
Re: Challenges (response to post by vexorian) | Reply
This is not a good idea in my opinion. If I am aware that the problem is particularly tricky and someone else submits a wrong solution, it just completely makes no sense to write a dumb code myself just to be able to challenge (moreover, this means another will get 1 extra challenge from me).
Re: Challenges (response to post by vexorian) | Reply
I don't think that's a good idea. In my experience, challenging is way more easy when I discover my solution is wrong but couldn't fix it. In many cases I don't submit the code because I don't like to be challenged or failed.

How about to impose a cool-time when someone fails challenge? 30 seconds or 1 minute seem good.
Re: Challenges (response to post by brunoja) | Reply
First off, I agree that there is no point to the restriction.

However, I'd like to present my side of the story. I believe you're referring to match http://community.topcoder.com/stat?c=coder_room_stats&cr=22897384&rd=16076&rm=323693.

You challenged my solution unsuccessfully. After your challenge, you typed something like "I can't believe that negative points can't challenge" into the room chat, and then repeatedly opened and closed my 250 solution. I find that to be inappropriate, as you are pretty much broadcasting to the room that you think my solution is incorrect, instead of letting them decide for themselves.

Furthermore, unlike what you claimed, no one else challenged my code. In fact, I went on to pass system tests. So what exactly was your challenge case?
Re: Challenges (response to post by chenmark) | Reply
"Furthermore, unlike what you claimed, no one else challenged my code. In fact, I went on to pass system tests. So what exactly was your challenge case?"
I was wrong about it.. But in my opinion the negative restriction is unfair and should be changed somehow.

"You challenged my solution unsuccessfully. After your challenge, you typed something like ..."
If I did open and close your problem, it was not with that purpose, I am sorry..
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