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Please remove the partial grading system in long contests.

I feel that this is absolutely not required. Long contest is a ten day contest. Going by that, contestants should be encouraged to go for full solutions rather than partials. Partial grading defeats the very purpose. Please don't have it next month onwards.

asked 17 Nov '14, 15:21

pushkarmishra's gravatar image

4★pushkarmishra
1.3k156581
accept rate: 4%

edited 17 Nov '14, 16:57

1

Who marked this as "community wiki" and why? This option is, according to my understanding, for editorials...

(17 Nov '14, 15:40) betlista ♦♦3★
2

My view is completely different to most. Keep the partial grading and remove the easy 4 problems. Everyone gets something to play with. :P

(18 Nov '14, 08:15) himanshujaju6★

15

I like the partial grading and I believe I'm not the only one...

There are few side-effect (I won't call it bugs), for example I do not want to have partially solved problem in my profile as solved - new category like partially solved would be great. Similar problem with marking solved problems on contest page.

On the other hand I believe, while CodeChef's long term goal is educating, this is beneficial. Good example can be Fombinatorial, for 9 points it's good for a beginner, 40 points were challenging for me too and 100 is good evaluation of your effort.

Yes, someone can disagree, that 10 point in one problem is not as easy to get as 10 points in another, so it is not balanced, but here I can say just one thing - the environment is the same for all contestants and is you choice which problem you want/are trying to solve...

From a long term point of view I think it is also better for competition, before it was so, that a lof of contestants are in one bucket, let say with 6 points, now there are more buckets...

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answered 17 Nov '14, 15:30

betlista's gravatar image

3★betlista ♦♦
16.9k49115225
accept rate: 11%

edited 17 Nov '14, 15:37

13

I will tell you my IOI experience. When I started programming and came to know that IOI had partial grading, I often used to focus on getting partial points rather than going for full solutions. Basic human instinct - maximisation of points. A beginner who managed to score 40 on Fombi would not make a real effort to move to 100. This happens; I know it pretty well. If there has to be a change, I would suggest that we can have different points depending on difficulty. Hard problems can be worth 3 points and easy worth 1. Partial grading in a 10 day contest is absolutely ridiculous.

(17 Nov '14, 15:36) pushkarmishra4★
2

Here I think the situation is different in long contest - you have a lot of time to implement first easier approach and later the more advanced one, while you have a lot of time to do so... Motivation is personal thing, for you it's a challenge maybe to get 20 WAs, for others it might be rewarding to have at least some points...

(17 Nov '14, 15:50) betlista ♦♦3★
5

OK, understand this. Partial grading allows for contestants to know whether their approach is entirely wrong or only on corner cases. This way, people tend to think less and, consequently, lose out on improving your debugging skills. Then, as one of the posters wrote, many inappropriate solutions pass because you get an idea of the test cases. Lastly, beginners tend to get satisfied with partial points and don't make the effort of scouring the internet for answers. In all, it is of no good except the fact that contestants just practice naive algos.

(17 Nov '14, 15:57) pushkarmishra4★
1

In Fombitorial, if there weren't any partial grading, perhaps, I wouldn't have attempted it.. But now, I know what Fermat little's theorem is and I could get 40 points! :) (Learning something new and getting more points because of it, feels really awesome) Partial grading helps :)

(17 Nov '14, 18:29) ajinkya1p35★
2

Even if you would have attempted the full problem you would have learnt of Fermat anyway, and much more. I don't see how having points for naive solutions makes people attempt those parts of the problem which they otherwise won't.

(17 Nov '14, 18:34) pushkarmishra4★

Yes, if you really want to encourage new programmers, divide everyone into categories.. Like topcoder or codeforces(div. 1, div. 2) and then put partial grading for one division. This isn't helping anyway..

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answered 17 Nov '14, 15:28

pranjalranjan's gravatar image

4★pranjalranjan
2.0k21432
accept rate: 20%

For example on CodeForces this is not working well - when there is contest for div 2 only few div 1 coders participate and that ruins the contest and makes it difficult to advance from div 2 to div 1.

(17 Nov '14, 16:22) betlista ♦♦3★

Completely Agree !!!!! it completely ruins the thrill and interest of a long contest ...

(also misguides) for eg. Fombinatorial(100 points) is harder to solve than Chef and Words (100 points) , but everyone gets a green colour on Fombinatorial getting 9 points which is not worthy of a solution .....

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answered 17 Nov '14, 15:31

dextrous's gravatar image

5★dextrous
1582210
accept rate: 0%

But the situation was the same in previous contests - you had just 1 point and it was not important how hard the problem was...

(17 Nov '14, 15:33) betlista ♦♦3★
2

I like the way you put it @dextrous. It actually ruins the thrill of managing to do the questions which <100 people have done.

(17 Nov '14, 15:37) pushkarmishra4★
1

1 point for each problem was scrutinized but partial grading is even worse .. when one see's that only one test case is wrong then he/she go for corner cases straightforward ... previously it made you think more about the problem with your solution ... it widens your way of thinking (sometimes corner case check and sometimes we have to completely change the approach)... partial scoring hints whether approach is wrong or only corner cases are left .!!!

(17 Nov '14, 15:38) dextrous5★

That's why I counted the statistics offline. You need more?

(17 Nov '14, 15:40) betlista ♦♦3★
1

you are correct on your point ... but these are just my personal views on the format ...

(17 Nov '14, 15:46) dextrous5★

Due to partial grading, the first 5 or 6 problems can be solved by Bruteforce only.So many people are getting more number of ACCEPTED's.PLZ CHANGE THE FORMAT.

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answered 17 Nov '14, 15:29

arghareturns's gravatar image

2★arghareturns
49
accept rate: 0%

2

I still cannot see the problem? Ok, they have some additional points, and? Someone solving the problem for 100 points has always higher rank.

(17 Nov '14, 15:35) betlista ♦♦3★

I think it's a very good initiative taken by codechef team by introducing partial grading system. I myself felt very motivated to get full points in the FNCS by trying so many times. By this i was able to know that my approach was right, giving right answer but was not the optimized one. So it helps the beginners and motivates them to try more and more so they can earn full points for the problem. This time i tried to attempt and solve the question that i would have left by seeing its acceptance rate in the old system. So i think it's good for the beginners. There are some drawbacks of the system like we are now not able to judge the problem complexity by seeing its accept rate and some others related to ranking. This may take time , we should give chance to codechef team to work on it. I'm sure that they will definitely come up with some solution.

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answered 17 Nov '14, 17:50

hardik94's gravatar image

2★hardik94
80118
accept rate: 0%

edited 17 Nov '14, 17:51

there are many other major problems you overlooked. One of them is the problem of hacking.

(17 Nov '14, 17:58) pushkarmishra4★

As I wrote in comment for this answer, problem is, that one can see which test cases failed, it's not partial grading problem.

(17 Nov '14, 18:15) betlista ♦♦3★

yes .. certainly!!! failed test cases must not be shown(it only promotes hacking) .. partial grading is okay ...

(17 Nov '14, 18:23) dextrous5★

@betlista I'm agree with you. One should only be able to see the test cases for which his/her answer is accepted. Otherwise only error should be displayed as WA,TLE etc..like in old system. Detailed information regarding test cases should not be displayed.

(18 Nov '14, 09:35) hardik942★

What you could have tried is to divide the tasks into subtasks and show subtask-specific information upon each submit. But, one would get score (1 point per problem) for a problem, only if all subtasks pass. (Hard-earned points!!!)

For folks who want to try harder problems, they can still get ideas on how and where they should optimize, but, unless and until they reach the final destination, no points.

Thoughts?

Disclaimer: Personal opinion.

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answered 18 Nov '14, 08:46

tijoforyou's gravatar image

2★tijoforyou
4.2k52364
accept rate: 15%

I personally feel otherwise , it is really good to have partial grading system , which really encourage and help the guy to progressively move to final most efficient solution. There is nothing bad in being helped by the contest to move and try in the right direction. At the end of the day it is the learning which makes you the better. Sometime because you keep on getting TLE there is no measurement of how far you have reached. This is my personal feeling.

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answered 17 Nov '14, 15:28

dev8546's gravatar image

2★dev8546
117110
accept rate: 0%

3

It's a long contest. You have ample time to judge and correct your approach to come up with the perfect solution in 10 days.

(17 Nov '14, 15:30) pranjalranjan4★

yes I completely back the idea that a partially solved question must not appear in the solved section of profile of a codechef user. Moreover, I will suggest that partial marking should me removed when contest's problems are introduced in practice arena,I think when someone is practising ,he must solve fully.

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answered 18 Nov '14, 07:54

amolsaxena25's gravatar image

3★amolsaxena25
511
accept rate: 0%

Partial grading system was good...but it had it's own flaws like i could solve 4 subtasks with one method sol1 and 2 subtasks with other approach sol2 . What i did was guessed what would the length of string in the last 2 cases and i combined both the solutions and voila AC final soln Once i got AC,i didn't even bother to check back the mistakes i made in either approaches.

Plus point :Due to this grading system, I attempted questions which i would have left.

So in my opinion, there should be 2-3 problems with partial grading,and the rest should be same as earlier :)

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answered 17 Nov '14, 15:44

asif_mak's gravatar image

1★asif_mak
7041611
accept rate: 19%

too much of hassle. Its better to remove it.

(17 Nov '14, 15:50) pushkarmishra4★

This "hacking" is your personal choice, it's not contest format problem...

(17 Nov '14, 15:53) betlista ♦♦3★
2

@betlista I couldn't have "hacked" If the verdict for each each task was not shown.

(17 Nov '14, 15:58) asif_mak1★

but why should a contest allow something like this. A good contest is capable of preventing such a thing. isn't it?

(17 Nov '14, 15:59) pushkarmishra4★
2

why to give a chance of hacking !!!

At one point of time when you are really frustrated getting WA's, even good coders may be tempted to "hack" .. there should be no mean of hacking(like in previous contests).. A good coder must know how to handle this frustration and come out with the opt solution in difficult situations all by himself !!!

(17 Nov '14, 16:03) dextrous5★

Ok, but we are talking about two different things here - one is, that there is partial grading and another is, that information for which test case you solution failed is visible, and the later is the problem, not the partial grading...

(17 Nov '14, 18:10) betlista ♦♦3★
showing 5 of 6 show all

I think that partial grading is a good move, but IMHO, there is an issue introduced. For instance, there is no clear objective about how difficult particular problem is. The excellent examplas are Fombinatorial and FCNS problems. If the grading system was like for the previous contests, then these problems would have very low percentage of AC. That percentage was a good indicator about the difficulty of each problem and I used to solve problems according to their difficulty. However, in this contest, solution Fombinatorial has a very high percentage of AC due to the fact that there were a lot of partially accepted solutions. To mitigate this issue, you should introduce a list of acceptance rate of fully accepted solution. In this manner, the contestants would be still able to solve solutions partially and learn more. On the other side, by having the list of acceptance rate of fully accepted solutions, the contestants would be able to get a good sense about problems difficulties.

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answered 17 Nov '14, 15:46

silke's gravatar image

4★silke
12014
accept rate: 0%

edited 17 Nov '14, 15:48

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question asked: 17 Nov '14, 15:21

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last updated: 18 Nov '14, 09:35