Announcement
IOI problems are here!
by bbi5291 on Aug 23, 2009 - 2:57:08 am UTC
I have begun to add the problems from past IOIs. This will probably be completed sometime within the next week. I am intentionally omitting interactive problems (these are difficult to set up right now; this will hopefully be fixed soon), problems for which I wasn't sure that the "official" solutions were actually optimal, and problems that already appear on the USACO training pages.
I know IOI seems a bit intimidating, but trust me, it is not as impossible as it may seem. Most IOI problems are far from trivial but in earlier years most of you should be able to get significant partial points on most of the problems (with a bit -- or maybe a lot -- of work, of course.)
Now, as these problems are being added in a hurry there wasn't enough time to fully check everything. I did not have time to write solutions to these problems, so I don't know how difficult they are. I will be examining submitted solutions and I may raise or lower the point value, or perhaps check/uncheck the partial score option depending on what seems fair. You can also complain if you think that the value is too low.
So far 11 of the problems have required custom judges (that is, it is not as simple as just checking if your output is the same as the judge output, so a different program is required to grade your output). And there are more to come. I had to write all of these and did not test them extensively. If your program seems to be giving correct output but it is marked wrong, or you think that the score you deserve on a testcase based on the grading info at the bottom of the problem statement is different than the score you got, tell me and I'll fix it. (Note that "judge output" can be misleading; in fact for most of these problems, if your program's output is the same as the "judge output" shown, it will be wrong.) Again, I will be monitoring submissions to try to catch these mistakes.
Finally, if there is something wrong with a problem statement (for example if the sample data was copied incorrectly) then obviously do tell so I can fix it.
I know IOI seems a bit intimidating, but trust me, it is not as impossible as it may seem. Most IOI problems are far from trivial but in earlier years most of you should be able to get significant partial points on most of the problems (with a bit -- or maybe a lot -- of work, of course.)
Now, as these problems are being added in a hurry there wasn't enough time to fully check everything. I did not have time to write solutions to these problems, so I don't know how difficult they are. I will be examining submitted solutions and I may raise or lower the point value, or perhaps check/uncheck the partial score option depending on what seems fair. You can also complain if you think that the value is too low.
So far 11 of the problems have required custom judges (that is, it is not as simple as just checking if your output is the same as the judge output, so a different program is required to grade your output). And there are more to come. I had to write all of these and did not test them extensively. If your program seems to be giving correct output but it is marked wrong, or you think that the score you deserve on a testcase based on the grading info at the bottom of the problem statement is different than the score you got, tell me and I'll fix it. (Note that "judge output" can be misleading; in fact for most of these problems, if your program's output is the same as the "judge output" shown, it will be wrong.) Again, I will be monitoring submissions to try to catch these mistakes.
Finally, if there is something wrong with a problem statement (for example if the sample data was copied incorrectly) then obviously do tell so I can fix it.
Comments (Search)
Are you allotting points based on relative difficulty of the problems?
Anyways, good job adding problems. :)
Programs always read from stdin and write to stdout, we just redirect the input and output. Most of the problems have custom judges, as I remarked.
Most of the time I just use a script to make a list of the data. It's just that making things custom gives us the option of batching, custom weighting, etc.
Yeah, I usually write a quick-and-dirty bash script like the following: [code] for i in {1..10} do echo blah/blah$i.in, blah/blah$i.out, 10 done [/code] The output is then pasted into the "Edit Problem" box, and this is internally parsed and stored in the database.The output is then pasted into the "Edit Problem" box, and this is internally parsed and stored in the database.
g++ -o blah -O2 blah.cpp
./blah < input.in
?