Computer Science Canada

Ccc2013

Author:  t68 [ Tue Feb 26, 2013 5:37 pm ]
Post subject:  Ccc2013

is it difficult?

Author:  Panphobia [ Tue Feb 26, 2013 6:27 pm ]
Post subject:  RE:Ccc2013

it was more difficult than past ones for me, havent you done it?

Author:  Unnamed [ Tue Feb 26, 2013 6:50 pm ]
Post subject:  Re: Ccc2013

How did you guys do? I got pretty low Sad

Author:  aldld [ Tue Feb 26, 2013 7:15 pm ]
Post subject:  Re: Ccc2013

Did anybody else have problems with the online grader? I somehow failed every test case on the grader for S1, yet when I compared my solution to others' it always gave the exact same result as theirs, yet they somehow got that one.

Not to mention that it took over an hour for the solutions to be graded.

I'm not sure if I can go into detail right at this moment, but this combined with a whole bunch of other things going wrong resulted in me getting a really really low score Sad

Author:  Halls McSmurfin [ Tue Feb 26, 2013 7:20 pm ]
Post subject:  Re: Ccc2013

The grader doesn't even work.
0/10, would not use again.
Grade F--.

Author:  Unnamed [ Tue Feb 26, 2013 7:28 pm ]
Post subject:  Re: Ccc2013

did anyone else have grader problems?

Author:  Panphobia [ Tue Feb 26, 2013 7:34 pm ]
Post subject:  RE:Ccc2013

i got the first three right in java lol,and then the grade messed up for q5 worked for test data but got 0/15 on grader

Author:  coolgod [ Tue Feb 26, 2013 7:40 pm ]
Post subject:  Re: Ccc2013

The grader worked in the morning and at lunch it was 20 min(according to notice) delay between feedback.
During the afternoon 20 min feedback delay turned in 90 (according to their notice on site.). In reality any solution after 3:20 (when we started) had no feedback provided.
Getting 1-4 perfect with feedback is much easier than without.

Author:  Panphobia [ Tue Feb 26, 2013 8:04 pm ]
Post subject:  RE:Ccc2013

oh nice what did you do for q4? what algorithm did you use?

Author:  bbi5291 [ Tue Feb 26, 2013 9:45 pm ]
Post subject:  Re: Ccc2013

Please don't discuss the problems until the end of the week.

Author:  linuxp [ Tue Feb 26, 2013 9:49 pm ]
Post subject:  Re: Ccc2013

bbi5291 @ Tue Feb 26, 2013 9:45 pm wrote:
Please don't discuss the problems until the end of the week.

can i discuss that freaking awesome judge system?
they used some advanced technology that made 90 minutes to 4 hours

Author:  aldld [ Tue Feb 26, 2013 10:13 pm ]
Post subject:  Re: Ccc2013

I'll wait before giving details about the questions, but I hope I can discuss the grading system because this really needs to be addressed. There are more problems with the judging system than just the time.

The day before the competition I did some tests at home with the online grader (with the 2012 questions available). For Python, something as simple as adding a class that does nothing causes the program to fail. Compare these two screenshots:

http://i.imgur.com/qNcxPN4.png
http://i.imgur.com/Rly97ze.png

Honestly this is ridiculous. This competition shouldn't even play a role in scholarship or university admission decisions if they can't even have a working grader. It would probably at least be easier to maintain if their system was more like that of Project Euler or Google Code Jam, where you do the actual running of the program on your own system. https://code.google.com/codejam/quickstart.html

Edit: Another thing worth mentioning: The printed problem booklet allows for 1 minute per test case, however the online grader cuts it off at 1-2 seconds... (5s for problem S5)

Author:  linuxp [ Tue Feb 26, 2013 10:53 pm ]
Post subject:  RE:Ccc2013

^ Agree
I got TLE on grader
but it's still inside 1 minute limit
What's the point to make such a online grader?
Witch one is the real instruction?

Where is official explanation ?

Author:  lagingking [ Wed Feb 27, 2013 12:01 am ]
Post subject:  RE:Ccc2013

Best CCC ever!!!
Not only does the grader not give any response in time, it also marks almost everything wrong !!!
Only if it happened to everyone, not just the people who used it later.
I mean, it would be unfair for those to suffer instant feedback because they are in different timezone, right?
Defnitely fair!
Very Happy
10/10
would definitely come again!!!!

Author:  bbi5291 [ Wed Feb 27, 2013 1:03 am ]
Post subject:  Re: Ccc2013

Guys, cut them some slack. Writing an autograder is tough, and this was the first time they've used this system. It's also harder to grade interpreted languages like Python than compiled languages like C++ and Pascal (don't even get me started on Java). I have complete confidence that the CEMC will sort out these issues and that everyone will be graded fairly.

Author:  aldld [ Wed Feb 27, 2013 1:52 am ]
Post subject:  Re: Ccc2013

bbi5291 @ Wed Feb 27, 2013 1:03 am wrote:
this was the first time they've used this system.


Actually they used it last year too, and it had problems then. They new tons of students would be uploading programs all at the same time, they should have known to stress test the grader beforehand.

Author:  bbi5291 [ Wed Feb 27, 2013 2:19 am ]
Post subject:  Re: Ccc2013

aldld @ Wed Feb 27, 2013 1:52 am wrote:
bbi5291 @ Wed Feb 27, 2013 1:03 am wrote:
this was the first time they've used this system.


Actually they used it last year too, and it had problems then. They new tons of students would be uploading programs all at the same time, they should have known to stress test the grader beforehand.
Wow, I stand corrected. Still, autograders are tricky to get right, so yeah.

Author:  Halls McSmurfin [ Wed Feb 27, 2013 3:56 am ]
Post subject:  Re: Ccc2013

aldld @ Wed Feb 27, 2013 1:52 am wrote:
bbi5291 @ Wed Feb 27, 2013 1:03 am wrote:
this was the first time they've used this system.


Actually they used it last year too, and it had problems then. They new tons of students would be uploading programs all at the same time, they should have known to stress test the grader beforehand.


What was wrong with the grader last year?

Author:  calaveras [ Wed Feb 27, 2013 12:03 pm ]
Post subject:  Re: Ccc2013

How about everybody's score by your school teacher initial grading ?

My score is 62 in Senior Division. ody

Anybody could expect what kind of score will be the cut off for CCC stage 2 ?

Thanks for everybody's input.

Peter

Author:  nullptr [ Wed Feb 27, 2013 12:04 pm ]
Post subject:  Re: Ccc2013

When are the test data released? Our school didn't get a grader (which looks like a good thing...).

Author:  calaveras [ Wed Feb 27, 2013 12:07 pm ]
Post subject:  Re: Ccc2013

By the way, the online grader is extremely slow.

After each submission, we get feedback after 20-50 minutes. How about the response time at your school ?

Our contest began at 12:00 yesterday, this might be the peak hour.

Author:  bbi5291 [ Wed Feb 27, 2013 12:57 pm ]
Post subject:  Re: Ccc2013

calaveras @ Wed Feb 27, 2013 12:03 pm wrote:
How about everybody's score by your school teacher initial grading ?

My score is 62 in Senior Division. ody

Anybody could expect what kind of score will be the cut off for CCC stage 2 ?

Thanks for everybody's input.

Peter
My prediction (which is usually wrong) is that the cutoff this year will be around 63.

Author:  Halls McSmurfin [ Wed Feb 27, 2013 2:10 pm ]
Post subject:  Re: Ccc2013

nullptr @ Wed Feb 27, 2013 12:04 pm wrote:
When are the test data released? Our school didn't get a grader (which looks like a good thing...).


Your teacher should have the test data. Ask him / her for it?
How can not using the grader be a good thing?

Author:  nullptr [ Wed Feb 27, 2013 2:29 pm ]
Post subject:  Re: Ccc2013

Halls McSmurfin @ Wed Feb 27, 2013 2:10 pm wrote:
nullptr @ Wed Feb 27, 2013 12:04 pm wrote:
When are the test data released? Our school didn't get a grader (which looks like a good thing...).


Your teacher should have the test data. Ask him / her for it?
How can not using the grader be a good thing?


It seemed like a big headache for a lot of people, and from the looks of it, it gave wrong answers sometimes too.

Author:  crossley7 [ Wed Feb 27, 2013 3:10 pm ]
Post subject:  RE:Ccc2013

The advantage of the grader is that you might be able ot get feedback during the contest while a teacher grading you only get marks after everything is done and basically get 1 submission. In general onlin graders aren't great, but I'm pretty confident that they work fine but they check output character by character so hidden spaces can ruin a program and cause it to be wrong even though it looks right.

If it is any reference, last year you needed a 64 to make round 2 but I haven't looked at this year's problems to see how they compare. But my guess is > 60 for sure if it is similar difficulty and 63 will be really tight.

The upside is that you wrote it. I believe that a bunch of schools couldn't write it this year with the teacher's strike

Author:  Panphobia [ Wed Feb 27, 2013 6:15 pm ]
Post subject:  RE:Ccc2013

The problem is that most of the people in my class, are idiots, no offence to them. So because they could not answer the questions they linked a random number generator to how many different answers there are and they submitted that program 50 times each, so imagine only 40 people in my class submitting 50 things to be graded per 4 questions.

Author:  bbi5291 [ Wed Feb 27, 2013 6:38 pm ]
Post subject:  Re: RE:Ccc2013

crossley7 @ Wed Feb 27, 2013 3:10 pm wrote:
If it is any reference, last year you needed a 64 to make round 2

For further reference: http://www.wcipeg.com/wiki/Canadian_Computing_Competition#Historical_cutoff_values

Author:  Tony [ Wed Feb 27, 2013 7:42 pm ]
Post subject:  RE:Ccc2013

It took DWITE a couple of years to run into and refine all of those issues. We previously saw crazy things along the lines of students submitting a zip file of their Visual Basic project as a "java" solution which made the compiler crash in very bad ways.

Author:  d310 [ Wed Feb 27, 2013 11:52 pm ]
Post subject:  Re: Ccc2013

They've started to regrade all solutions on the online grader.

Author:  Unnamed [ Wed Feb 27, 2013 11:56 pm ]
Post subject:  Re: Ccc2013

d310 @ Wed Feb 27, 2013 11:52 pm wrote:
They've started to regrade all solutions on the online grader.


Will it be regraded with a 1 minute time limit?

Author:  d310 [ Thu Feb 28, 2013 12:12 am ]
Post subject:  Re: Ccc2013

No, standard time limits of 1 second, and 6 seconds.

Author:  y4y [ Thu Feb 28, 2013 12:45 am ]
Post subject:  RE:Ccc2013

I had an interesting idea.
I too wanted the test cases and thought that it's possible to extract them using the online grader.

idk how restricted the submissions are but my idea was to have python code that simply posts all the input to some page where you have code to log said data.

btw it's too late now.... and this I didn't really plan on doing it just a thought

Author:  bbi5291 [ Thu Feb 28, 2013 12:59 am ]
Post subject:  Re: RE:Ccc2013

y4y @ Thu Feb 28, 2013 12:45 am wrote:
I had an interesting idea.
I too wanted the test cases and thought that it's possible to extract them using the online grader.

idk how restricted the submissions are but my idea was to have python code that simply posts all the input to some page where you have code to log said data.

btw it's too late now.... and this I didn't really plan on doing it just a thought

http://cemclinux1.math.uwaterloo.ca/ wrote:
Any unauthorized access, attempts to circumvent the security controls, or abuse of the system will result in DISQUALIFICATION from all contests.

Also, it probably won't work. It's straightforward to prevent processes from opening sockets.

Author:  Tony [ Thu Feb 28, 2013 1:03 am ]
Post subject:  RE:Ccc2013

not that unique of an idea. DWITE prevents that by evaluating submissions from within a VM that blocks outbound network connections.

in CCC's case my understanding is that the handful of people that make the Stage 2 cutoff get their submissions reviewed; so such would simply get you disqualified.

Author:  y4y [ Thu Feb 28, 2013 2:34 am ]
Post subject:  Re: RE:Ccc2013

Tony @ Thu Feb 28, 2013 1:03 am wrote:
not that unique of an idea. DWITE prevents that by evaluating submissions from within a VM that blocks outbound network connections.

in CCC's case my understanding is that the handful of people that make the Stage 2 cutoff get their submissions reviewed; so such would simply get you disqualified.


alright then, seems like a simple solution, I didn't even think that far ahead.
Like I said I wasn't planning on doing it and thought there might already be countermeasures against it.
It was just a thought that popped in my head, I don't even know python but knew that it had easy to use built in libraries for sockets/http requests.

btw this system does interest me how did you build the dwite system or similar grading systems?
Is there some form of open source code for platforms like this?

and is it true that this is the system used at UW by compsci profs?

sorry if I'm going a bit off topic, just interested that's all.

Author:  Tony [ Thu Feb 28, 2013 1:26 pm ]
Post subject:  RE:Ccc2013

Dan can better talk about DWITE's internals. In short, there's a front end that takes submissions and a backend that is running a queue of grading tasks. The grading happens in a controlled environment via the use of VMs.

UW does not use DWITE's tech, but some profs do use automated grading systems in class (this works very well for compiler courses). The name of the system escapes me at the moment.

Author:  linuxp [ Thu Feb 28, 2013 6:29 pm ]
Post subject:  Re: Ccc2013

d310 @ Thu Feb 28, 2013 12:12 am wrote:
No, standard time limits of 1 second, and 6 seconds.


But rule No.11 on instruction booklet says: " The Senior problems be given one minute of execution time per test case on a Pentium-4 class computer running at 2GHz, and similarly, one minute of execution time on the on-line grader. "

Cool

O_O

@_@ @_@ @_@

Liars?

Author:  coolgod [ Thu Feb 28, 2013 7:23 pm ]
Post subject:  Re: Ccc2013

Anyone else's score went down during the remark on the online graded? Mine went down 7 marks for #4.

Author:  bbqchps [ Thu Feb 28, 2013 7:37 pm ]
Post subject:  Re: Ccc2013

linuxp @ Thu Feb 28, 2013 6:29 pm wrote:
d310 @ Thu Feb 28, 2013 12:12 am wrote:
No, standard time limits of 1 second, and 6 seconds.


But rule No.11 on instruction booklet says: " The Senior problems be given one minute of execution time per test case on a Pentium-4 class computer running at 2GHz, and similarly, one minute of execution time on the on-line grader. "

Cool

O_O

@_@ @_@ @_@

Liars?

I was wondering if anyone had clarification on this as well Neutral

Author:  Panphobia [ Thu Feb 28, 2013 11:29 pm ]
Post subject:  RE:Ccc2013

Is this strange or not? I just handed in the exact program for question 2, on the post contest, and I got 15/15, but when I did it on Tuesday, I got 6/15?

Author:  dnkywin [ Fri Mar 01, 2013 10:30 am ]
Post subject:  RE:Ccc2013

Has anyone heard of anyone who's gotten 75/75 yet? #5 was pretty difficult :/

Author:  Halls McSmurfin [ Fri Mar 01, 2013 11:10 am ]
Post subject:  Re: RE:Ccc2013

Panphobia @ Thu Feb 28, 2013 11:29 pm wrote:
Is this strange or not? I just handed in the exact program for question 2, on the post contest, and I got 15/15, but when I did it on Tuesday, I got 6/15?


Check your submissions during the contest again; they were rejudged.

Author:  crossley7 [ Fri Mar 01, 2013 1:26 pm ]
Post subject:  RE:Ccc2013

For the 1 minute problem, if it is taking your solution a minute to run, I can guarantee you are not doing it properly or you are using a language with ridiculous amounts of overhead.

Also, if you take the computer they are referencing, that is about 1-6 seconds on the waterloo computers which is where I suspect they are running them off of. Might be a bit more time but you really aren't losing much. The number of operations performed in 1 second is enormous.

Waterloo profs use a system called marmoset which is very similar to the CCC system but it is a different one.

Author:  linuxp [ Fri Mar 01, 2013 4:17 pm ]
Post subject:  Re: RE:Ccc2013

crossley7 @ Fri Mar 01, 2013 1:26 pm wrote:
For the 1 minute problem, if it is taking your solution a minute to run, I can guarantee you are not doing it properly or you are using a language with ridiculous amounts of overhead.

Also, if you take the computer they are referencing, that is about 1-6 seconds on the waterloo computers which is where I suspect they are running them off of. Might be a bit more time but you really aren't losing much. The number of operations performed in 1 second is enormous.

Waterloo profs use a system called marmoset which is very similar to the CCC system but it is a different one.


I don't know am i using a pro algorithm, but my solution get 75/75 in 1 minute limit, but only 65 in 1/6s limit.
The problem is they gave us wrong information.
Just imagine if your teacher gave you an essay and told you 800 words minimum.
But after you hand it in, your teacher tells you, OMG sorry bro, it was 2000 words minimum, you all lose 20% mark for that.
What's your feelings?

Author:  ttm [ Fri Mar 01, 2013 5:20 pm ]
Post subject:  Re: Ccc2013

I didn't use the online grader but my solution to S5 ran in <3 seconds for all cases...

Author:  Halls McSmurfin [ Fri Mar 01, 2013 5:53 pm ]
Post subject:  Re: Ccc2013

ttm @ Fri Mar 01, 2013 5:20 pm wrote:
I didn't use the online grader but my solution to S5 ran in <3 seconds for all cases...


Wow.. that's very impressive. Did you also get perfect?

Author:  ttm [ Fri Mar 01, 2013 6:30 pm ]
Post subject:  Re: Ccc2013

Yeah. It was a 7 liner Smile

crossley7 wrote:

The number of operations performed in 1 second is enormous.


Um.. yeah but have you seen the size of the test cases for S4? Some of my classmates' solutions (in Ruby) cut it close at > 40 seconds for the larger cases. I'd have no idea how to solve 4 if I was using Turing (but I suppose that counts as a language with ridiculous amounts of overhead).[/quote]

Author:  nullptr [ Fri Mar 01, 2013 6:44 pm ]
Post subject:  Re: Ccc2013

What's this about a postcontest? Can I test my solutions there? (I don't have any login info)

Author:  ishiney [ Fri Mar 01, 2013 6:55 pm ]
Post subject:  RE:Ccc2013

For those complaining about the 1/6s - 1 min judge time, here's the reply I got from Mr. Troy Vasiga, the person in charge of CCC (according to the CEMC website):

Quote:
"1 minute" of real time (i.e., user time) is roughly the same as "5 seconds" of CPU time. So, it should actually be roughly equal.


So there you go Smile

Author:  bbqchps [ Fri Mar 01, 2013 7:38 pm ]
Post subject:  Re: RE:Ccc2013

ishiney @ Fri Mar 01, 2013 6:55 pm wrote:
For those complaining about the 1/6s - 1 min judge time, here's the reply I got from Mr. Troy Vasiga, the person in charge of CCC (according to the CEMC website):

Quote:
"1 minute" of real time (i.e., user time) is roughly the same as "5 seconds" of CPU time. So, it should actually be roughly equal.


So there you go Smile


Thanks for asking! I have still have a question though... Only the last problem was given 5s to run, but wasn't the one minute time limit in place for each of the problems (based on the instruction booklet at least)Question

Author:  ishiney [ Fri Mar 01, 2013 8:21 pm ]
Post subject:  RE:Ccc2013

I agree that the official answer regarding the time limits isn't perfect. For example, after slightly modifying my algorithm to calculate the answers for all N <= 5 million (for S5), it ran under 30s (though my 2.5 GHz laptop is slightly higher than the specified specification), but TLE'd on the judge computer. There's not much we can really do about it at this point, though, besides send hate mail (just kidding Smile ).

However, I do believe that even a slightly optimized algorithm (i.e. that's not completely brute-force) should pass most of the test cases for S5 under the 5s time limit....

Author:  bbqchps [ Fri Mar 01, 2013 8:40 pm ]
Post subject:  Re: RE:Ccc2013

Haha, I'm actually referring to Q4 which I made a bit of a careless mistake so it TLE'd, but I'm pretty sure that it was at least fast enough to run under 1 minute.

Q5 is really just a 10 line "solution" Razz

Author:  Panphobia [ Fri Mar 01, 2013 9:02 pm ]
Post subject:  Re: Ccc2013

Could anyone point out what I did wrong in question number 3, I got the sample output correct on both cases, but I seemed to have failed the testing
Java:
import java.util.*;

public class Main {

    static int teamWin = 0;

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        while (s.hasNext()) {
            int team = Integer.parseInt(s.nextLine());
            int n = Integer.parseInt(s.nextLine());
            ArrayList<String> nums = new ArrayList<String>();
            nums.add("1 2");
            nums.add("1 3");
            nums.add("1 4");
            nums.add("2 3");
            nums.add("2 4");
            nums.add("3 4");
            ArrayList<String[]> text = new ArrayList<String[]>();
            int[] scores = {0, 0, 0, 0};
            for (int i = 0; i < n; ++i) {
                text.add(s.nextLine().split(" "));
                if (Integer.parseInt(text.get(i)[2]) > Integer.parseInt(text.get(i)[3])) {
                    scores[Integer.parseInt(text.get(i)[0]) - 1] += 3;
                } else if (Integer.parseInt(text.get(i)[2]) < Integer.parseInt(text.get(i)[3])) {
                    scores[Integer.parseInt(text.get(i)[1]) - 1] += 3;
                } else {
                    scores[Integer.parseInt(text.get(i)[1]) - 1]++;
                    scores[Integer.parseInt(text.get(i)[0]) - 1]++;
                }
            }
            for (int i = 0; i < n; ++i) {
                nums.remove(nums.indexOf(text.get(i)[0] + " " + text.get(i)[1]));
            }

            ArrayList<int[]> points = new ArrayList<int[]>();
            for (int i = 0; i < nums.size(); ++i) {
                int[] num = {nums.get(i).charAt(0) - '0', nums.get(i).charAt(2) - '0'};
                points.add(num);
            }
            recurse(points, scores, team);
            System.out.println(teamWin);
        }

    }

    public static void recurse(ArrayList<int[]> points, int[] score, int team) {
        if (points.isEmpty()) {
            for (int i = 0; i < 4; ++i) {
                if (i != team - 1) {
                    if (score[team - 1] < score[i]) {
                        return;
                    }
                }
            }
            teamWin++;
        } else {
            int[] lol = points.get(0);
            score[lol[0] - 1] += 3;
            ArrayList<int[]> a = new ArrayList<int[]>();
            for (int i = 0; i < points.size(); ++i) {
                if (i != points.indexOf(lol)) {
                    a.add(points.get(i));
                }
            }
            recurse(a, score, team);
            score[lol[0] - 1] -= 3;
            score[lol[1] - 1] += 3;
            a.clear();
            for (int i = 0; i < points.size(); ++i) {
                if (i != points.indexOf(lol)) {
                    a.add(points.get(i));
                }
            }
            recurse(a, score, team);
            score[lol[1] - 1] -= 3;
            score[lol[0] - 1]++;
            score[lol[1] - 1]++;
            a.clear();
            for (int i = 0; i < points.size(); ++i) {
                if (i != points.indexOf(lol)) {
                    a.add(points.get(i));
                }
            }
            recurse(a, score, team);
            score[lol[0] - 1]--;
            score[lol[1] - 1]--;
        }
    }
}

Author:  nullptr [ Fri Mar 01, 2013 9:36 pm ]
Post subject:  Re: Ccc2013

Panphobia @ Fri Mar 01, 2013 9:02 pm wrote:
Could anyone point out what I did wrong in question number 3, I got the sample output correct on both cases, but I seemed to have failed the testing
Java:
import java.util.*;

public class Main {
    ...
}


It looks like your program counts ties as wins... they really should have included a test case for that.

Author:  Panphobia [ Fri Mar 01, 2013 9:43 pm ]
Post subject:  RE:Ccc2013

yea I just changed from < to <= and I got perfect in all cases lol

Author:  Panphobia [ Fri Mar 01, 2013 9:44 pm ]
Post subject:  RE:Ccc2013

Well I couldve gotten 65 points.....

Author:  linuxp [ Fri Mar 01, 2013 10:09 pm ]
Post subject:  Re: RE:Ccc2013

ishiney @ Fri Mar 01, 2013 6:55 pm wrote:
For those complaining about the 1/6s - 1 min judge time, here's the reply I got from Mr. Troy Vasiga, the person in charge of CCC (according to the CEMC website):

Quote:
"1 minute" of real time (i.e., user time) is roughly the same as "5 seconds" of CPU time. So, it should actually be roughly equal.


So there you go Smile



I have to tell you something really sad

For S4, if i use cin as input result is tle
but if i change cin to scanf, result is prefect.
Can you say my algorithm is bad? it's not even close to roughly equal.

Author:  coolgod [ Fri Mar 01, 2013 10:46 pm ]
Post subject:  Re: Ccc2013

Guide to getting high scores on CCC.
learn c and use c inputs instead of C++. This is the only contest I've seen where a c++ solution does not run in time but a c one does.

Author:  bbi5291 [ Fri Mar 01, 2013 11:18 pm ]
Post subject:  Re: Ccc2013

coolgod @ Fri Mar 01, 2013 10:46 pm wrote:
Guide to getting high scores on CCC.
learn c and use c inputs instead of C++. This is the only contest I've seen where a c++ solution does not run in time but a c one does.

Then you haven't seen a lot of contests.

Author:  crossley7 [ Fri Mar 01, 2013 11:21 pm ]
Post subject:  Re: Ccc2013

ttm @ Fri Mar 01, 2013 6:30 pm wrote:
Yeah. It was a 7 liner Smile

crossley7 wrote:

The number of operations performed in 1 second is enormous.


Um.. yeah but have you seen the size of the test cases for S4? Some of my classmates' solutions (in Ruby) cut it close at > 40 seconds for the larger cases. I'd have no idea how to solve 4 if I was using Turing (but I suppose that counts as a language with ridiculous amounts of overhead).


Yes, Turing has a ridiculous amount of overhead. Haskell/C/C++/Java are the ones I was mainly considering. I don't know anything about ruby, but even python which is popular is much slower than the other ones I mentioned. Turing should not be used for the senior contest by anyone imo since a) it doesn't get used outside of a high school classroom and even then it's rarely used there, b) it is about a bazillion times slower than any decent language, and c) if the goal is to move to the next round you need to use something else that is drastically different anyways so you may as well qualify and practice with the allowed language.

I won't say Turing doesn't have uses, the thing is that none of those uses apply to contests.

Also, I have not seen test cases for any question nor have I seen the actual questions (I've got enough University schoolwork keeping me busy enough as is... though practice would be smart) I know what it is like for the time limit and my solution for S4 last year timed out on 3 of 5 cases given a minute (though not on the grader) but the other 2 were done in under 5 seconds.

Author:  ishiney [ Sat Mar 02, 2013 8:43 am ]
Post subject:  Re: Ccc2013

bbi5291 @ Fri Mar 01, 2013 11:18 pm wrote:
coolgod @ Fri Mar 01, 2013 10:46 pm wrote:
Guide to getting high scores on CCC.
learn c and use c inputs instead of C++. This is the only contest I've seen where a c++ solution does not run in time but a c one does.

Then you haven't seen a lot of contests.


I personally think there's nothing inherently unfair with the fact that i/o with scanf/printf is faster than their cin/cout counterparts, or BufferedReader vs. Scanner, or just Python, etc. Though it would have been nice if there were a note about this on the instructions somewhere on the site. In comparison, USACO tells you bluntly that C-styled i/o is faster than C++ streams; to use BufferedReader rather than Scanner; and that Python should not be used for large inputs. I guess this is just something that comes with experience. Sad

Author:  ishiney [ Sat Mar 02, 2013 9:55 am ]
Post subject:  RE:Ccc2013

Are we allowed to talk about the problems/solutions yet?

Author:  linuxp [ Sat Mar 02, 2013 11:02 am ]
Post subject:  Re: RE:Ccc2013

ishiney @ Sat Mar 02, 2013 9:55 am wrote:
Are we allowed to talk about the problems/solutions yet?


mmhs.ca already posted solution for s1-4 in python
The funny thing is python cannot solve s4 perfectly no matter what Razz

Author:  nullptr [ Sat Mar 02, 2013 12:02 pm ]
Post subject:  Re: RE:Ccc2013

linuxp @ Sat Mar 02, 2013 11:02 am wrote:
ishiney @ Sat Mar 02, 2013 9:55 am wrote:
Are we allowed to talk about the problems/solutions yet?


mmhs.ca already posted solution for s1-4 in python
The funny thing is python cannot solve s4 perfectly no matter what Razz


Do you mean http://access.mmhs.ca/ccc/index.htm ? Cause I can't find it anywhere..

Author:  ishiney [ Sat Mar 02, 2013 12:25 pm ]
Post subject:  Re: RE:Ccc2013

linuxp @ Sat Mar 02, 2013 11:02 am wrote:
ishiney @ Sat Mar 02, 2013 9:55 am wrote:
Are we allowed to talk about the problems/solutions yet?


mmhs.ca already posted solution for s1-4 in python
The funny thing is python cannot solve s4 perfectly no matter what Razz


That seems to be true. I re-coded S4 in Python, with all the optimizations I know - can't get more than 8/15. Python really need an efficient vector or ArrayList equivalent ... but since it's dynamically typed, it probably wouldn't Razz

Author:  azneye [ Sat Mar 02, 2013 12:52 pm ]
Post subject:  Re: RE:Ccc2013

nullptr @ Sat Mar 02, 2013 12:02 pm wrote:
linuxp @ Sat Mar 02, 2013 11:02 am wrote:
ishiney @ Sat Mar 02, 2013 9:55 am wrote:
Are we allowed to talk about the problems/solutions yet?


mmhs.ca already posted solution for s1-4 in python
The funny thing is python cannot solve s4 perfectly no matter what Razz


Do you mean http://access.mmhs.ca/ccc/index.htm ? Cause I can't find it anywhere..


My school website was moved here: http://mmhs.ca/ccc/index.htm

Author:  Raknarg [ Sat Mar 02, 2013 1:04 pm ]
Post subject:  RE:Ccc2013

Did you guys do the junior or senior questions?

Author:  nullptr [ Sat Mar 02, 2013 1:25 pm ]
Post subject:  Re: RE:Ccc2013

azneye @ Sat Mar 02, 2013 12:52 pm wrote:
nullptr @ Sat Mar 02, 2013 12:02 pm wrote:
linuxp @ Sat Mar 02, 2013 11:02 am wrote:
ishiney @ Sat Mar 02, 2013 9:55 am wrote:
Are we allowed to talk about the problems/solutions yet?


mmhs.ca already posted solution for s1-4 in python
The funny thing is python cannot solve s4 perfectly no matter what Razz


Do you mean http://access.mmhs.ca/ccc/index.htm ? Cause I can't find it anywhere..


My school website was moved here: http://mmhs.ca/ccc/index.htm


Thanks a lot!! Any reason why there's no S5 solution?

Author:  linuxp [ Sat Mar 02, 2013 1:27 pm ]
Post subject:  Re: RE:Ccc2013

ishiney @ Sat Mar 02, 2013 12:25 pm wrote:
linuxp @ Sat Mar 02, 2013 11:02 am wrote:
ishiney @ Sat Mar 02, 2013 9:55 am wrote:
Are we allowed to talk about the problems/solutions yet?


mmhs.ca already posted solution for s1-4 in python
The funny thing is python cannot solve s4 perfectly no matter what Razz


That seems to be true. I re-coded S4 in Python, with all the optimizations I know - can't get more than 8/15. Python really need an efficient vector or ArrayList equivalent ... but since it's dynamically typed, it probably wouldn't Razz


NO! you are wrong. The real suck point of S4 is input.
CCC should consider some languages have slow input.
for example: python input(), c++ cin, turing, ruby etc...
Python solution only need less than 0.1 second for solving largest cases
But it took more than 5s to get input.
It's just ridiculous.

Log files:
unknown
case: s4.6-1.in
reading :5.623000
solving: 0.088000
all: 5.711000

unknown
case: s4.6-2.in
reading :5.722000
solving: 0.054000
all: 5.776000

yes
case: s4.6-3.in
reading :5.691000
solving: 0.214000
all: 5.905000

no
case: s4.6-4.in
reading :5.753000
solving: 0.094000
all: 5.847000

no
case: s4.6-5.in
reading :5.656000
solving: 0.272000
all: 5.928000

Author:  bbi5291 [ Sat Mar 02, 2013 2:33 pm ]
Post subject:  Re: Ccc2013

So what do you expect them to do? Give you a longer time limit for C++ than for C? That would be ridiculous, because then you could just use C input functions in C++, and then you'd have an unfair advantage over the C people.

Giving all programming languages equal execution time is the least evil of all choices.

Also, did any of you actually bother to test your programs on huge cases, to be sure they wouldn't time out? If you had, you would've known that cin wouldn't cut it.

Author:  ishiney [ Sat Mar 02, 2013 5:13 pm ]
Post subject:  Re: Ccc2013

bbi5291 @ Sat Mar 02, 2013 2:33 pm wrote:
So what do you expect them to do? Give you a longer time limit for C++ than for C? That would be ridiculous, because then you could just use C input functions in C++, and then you'd have an unfair advantage over the C people.

Giving all programming languages equal execution time is the least evil of all choices.

Also, did any of you actually bother to test your programs on huge cases, to be sure they wouldn't time out? If you had, you would've known that cin wouldn't cut it.


I agree. Besides, Python/Java had lots of other "unfair" advantages*, one might say, in their standard libraries. Should we allow C++ contestants to use the Boost libraries or such as well? It's a slippery slope...

Edit: advantages such as BigInteger, built-in Geometry libraries (for Java at least), regex, even GregorianCalendar, HASHMAPS/SETS ... it's actually unfair. D:

Author:  ishiney [ Sat Mar 02, 2013 5:30 pm ]
Post subject:  RE:Ccc2013

So, maybe some actual discussions about the questions now?

I think S1 and 2 were adhoc, 3 was a simulation/complete search, 4 was a simple DFS/BFS, and 5 was a DP + Dijkstra (I only got 13/15 even after optimizing like crazy though =__=)

I know 1 person who did get a perfect score on S5. I'll ask for his code/algorithm....

Author:  linuxp [ Sat Mar 02, 2013 5:37 pm ]
Post subject:  RE:Ccc2013

My friend got perfect on S5 using Java.
He said its some kind of Math approach.
For 5000000 his program only used 0.x second.

Author:  Unnamed [ Sat Mar 02, 2013 5:40 pm ]
Post subject:  Re: Ccc2013

S5: I know someone with a 15/15 C++ solution that runs in 0.00X s or 0 s for all cases.

Author:  Halls McSmurfin [ Sat Mar 02, 2013 5:43 pm ]
Post subject:  Re: Ccc2013

I know someone with a < 1.7s run time for the largest cases in S4 with Python, too bad it doesn't pass the grader. lol...

Author:  Panphobia [ Sat Mar 02, 2013 5:45 pm ]
Post subject:  RE:Ccc2013

S4 wasn't difficult, it was a simple graph search problem, gotta love breadth first search. S5 you could use recursion, but a dynamic solution would be better.

Author:  coolgod [ Sat Mar 02, 2013 9:13 pm ]
Post subject:  Re: Ccc2013

bbi5291 @ Sat Mar 02, 2013 2:33 pm wrote:
So what do you expect them to do? Give you a longer time limit for C++ than for C? That would be ridiculous, because then you could just use C input functions in C++, and then you'd have an unfair advantage over the C people.

Giving all programming languages equal execution time is the least evil of all choices.

Also, did any of you actually bother to test your programs on huge cases, to be sure they wouldn't time out? If you had, you would've known that cin wouldn't cut it.


How exactly did u bother to test your program on huge cases? Remember most of us were given no feedback.
Generate millions of numbers and write it in a text file?
Suppose our computer c++ with cin could run under 1 second, that doesn't mean online grader can. Did anyone get a 15/15 without using c style inputs?

Author:  ttm [ Sat Mar 02, 2013 9:14 pm ]
Post subject:  Re: Ccc2013

For 5 you could use DP but that's still pretty slow. I solved it like so:
code:

#include <iostream>
int bestprime[] = { [huge list of pre-calculated values] };
int primes[] = { [huge list of pre-calculated values] };
int main() {
        freopen("s5.in", "r", stdin);
        int n, acc = 0; std::cin >> n;
        for (int pn = 0; n != 1; ++pn) while (n % primes[pn] == 0) n /= primes[pn], acc += bestprime[pn];
        std::cout << acc << std::endl;
}

Author:  Raknarg [ Sat Mar 02, 2013 9:56 pm ]
Post subject:  RE:Ccc2013

With s5 my friend did something interesting, that would work if he found an efficient method for finding factors. He basically created a map of finding to shortest path to separate numbers so he could reuse the data rather than straight bruteforcing it.

OF course it's still an n^2 algorithm if he has to search to find all the factors too.

I solved 4 with simple recursion. But i figured it out after the contest, so im kindof pissed -.-'

Author:  toofresh [ Sat Mar 02, 2013 10:02 pm ]
Post subject:  Re: Ccc2013

coolgod @ Sat Mar 02, 2013 9:13 pm wrote:
Did anyone get a 15/15 without using c style inputs?


Easy.

code:


#include <iostream>
#include <cstring>

using namespace std;

int N,M,cf,ct,p,q,pq,qp,target;
int hist[1000000];
int from[1000001];
int store[10000000];
int data[10000000][2];
char visited[1000000];

void dfs(int v) {
        for(int i = from[v]; i < from[v+1] && !visited[target]; i++) {
                if(visited[store[i]])
                        continue;
                visited[store[i]] = 1;
                dfs(store[i]); 
        }
}

int main() {
        cin >> N >> M;
        memset(hist,0,N*sizeof(int));
        memset(from,0,N*sizeof(int));
        for(int i = 0; i < M; i++) {
                cin >> data[i][0] >> data[i][1];
                data[i][0]--;
                data[i][1]--;
                hist[data[i][0]]++;
        }
        for(int i = 1; i < N; i++)
                from[i] = from[i-1]+hist[i-1];
        from[N] = M;
        for(int i = 0; i < M; i++) {
                cf = data[i][0];
                store[from[cf]+(--hist[cf])] = data[i][1];
        }
        cin >> p >> q;
        p--;
        q--;
        memset(visited,0,N);
        target = q;
        dfs(p);
        pq = visited[q];
        memset(visited,0,N);
        target = p;
        dfs(q); 
        qp = visited[p];
        if(pq && !qp)
                cout << "yes" << endl;
        else if(qp && !pq)
                cout << "no" << endl;
        else
                cout << "unknown" << endl;
}



This runs in 0.85 seconds on their grader. Shocked

Author:  Panphobia [ Sat Mar 02, 2013 10:09 pm ]
Post subject:  Re: RE:Ccc2013

Raknarg @ Sat Mar 02, 2013 9:56 pm wrote:
With s5 my friend did something interesting, that would work if he found an efficient method for finding factors. He basically created a map of finding to shortest path to separate numbers so he could reuse the data rather than straight bruteforcing it.

OF course it's still an n^2 algorithm if he has to search to find all the factors too.

I solved 4 with simple recursion. But i figured it out after the contest, so im kindof pissed -.-'
I solved it with a breadth first search, no more than 20 lines of code Smile

Author:  Raknarg [ Sat Mar 02, 2013 10:15 pm ]
Post subject:  RE:Ccc2013

blegh, at first I tried doing this weird linked list thing, which would have worked, it was just really messy and complicated. Turns out the answer was staring me right in the face, cause I was doing the easy search method in a really complex way cause I was just trying to save it... ugh

Author:  Panphobia [ Sat Mar 02, 2013 10:25 pm ]
Post subject:  Re: RE:Ccc2013

Raknarg @ Sat Mar 02, 2013 10:15 pm wrote:
blegh, at first I tried doing this weird linked list thing, which would have worked, it was just really messy and complicated. Turns out the answer was staring me right in the face, cause I was doing the easy search method in a really complex way cause I was just trying to save it... ugh
what school do you go to?

Author:  Raknarg [ Sat Mar 02, 2013 10:49 pm ]
Post subject:  RE:Ccc2013

Woodroffe High School, why?

Author:  Panphobia [ Sat Mar 02, 2013 11:00 pm ]
Post subject:  RE:Ccc2013

I don't know was just wondering.

Author:  linuxp [ Sat Mar 02, 2013 11:14 pm ]
Post subject:  Re: RE:Ccc2013

Panphobia @ Sat Mar 02, 2013 10:09 pm wrote:
I solved it with a breadth first search, no more than 20 lines of code Smile


Did you s5 code run in time(6s limit) for all cases?

Author:  toofresh [ Sat Mar 02, 2013 11:22 pm ]
Post subject:  RE:Ccc2013

Thought the time limit for s5 was 5 seconds...

Author:  Panphobia [ Sat Mar 02, 2013 11:26 pm ]
Post subject:  RE:Ccc2013

for s5 i only got a few test cases, but for s4 i got all but 5, the 5 i didnt timed out

Author:  Raknarg [ Sat Mar 02, 2013 11:34 pm ]
Post subject:  RE:Ccc2013

Im pretty sure the questions had a 1 minute limit

Author:  Panphobia [ Sat Mar 02, 2013 11:51 pm ]
Post subject:  Re: Ccc2013

this was for number 4 Posted Image, might have been reduced in size. Click Image to view fullscreen.[/img]

Author:  linuxp [ Sun Mar 03, 2013 1:52 am ]
Post subject:  Re: RE:Ccc2013

Raknarg @ Sat Mar 02, 2013 11:34 pm wrote:
Im pretty sure the questions had a 1 minute limit


The online grader changed time limit to 1 second for s1-4 and 6s for s5.
Evil or Very Mad

Author:  nullptr [ Sun Mar 03, 2013 5:47 pm ]
Post subject:  Re: Ccc2013

My solution for S5 takes about 45 seconds on my own computer (which is about 2 GHz). Will it get full marks?

Author:  Halls McSmurfin [ Sun Mar 03, 2013 6:11 pm ]
Post subject:  Re: Ccc2013

nullptr @ Sun Mar 03, 2013 5:47 pm wrote:
My solution for S5 takes about 45 seconds on my own computer (which is about 2 GHz). Will it get full marks?


No

Author:  ishiney [ Sun Mar 03, 2013 6:41 pm ]
Post subject:  Re: Ccc2013

nullptr @ Sun Mar 03, 2013 5:47 pm wrote:
My solution for S5 takes about 45 seconds on my own computer (which is about 2 GHz). Will it get full marks?


Why not enter it in yourself? http://cemclinux1.math.uwaterloo.ca/index.php
The Post-contest page is for trying out your code again, I think.

Author:  nullptr [ Sun Mar 03, 2013 6:59 pm ]
Post subject:  Re: Ccc2013

ishiney @ Sun Mar 03, 2013 6:41 pm wrote:
nullptr @ Sun Mar 03, 2013 5:47 pm wrote:
My solution for S5 takes about 45 seconds on my own computer (which is about 2 GHz). Will it get full marks?


Why not enter it in yourself? http://cemclinux1.math.uwaterloo.ca/index.php
The Post-contest page is for trying out your code again, I think.


Our school didn't get a grader for some reason, so I don't have any login info.

Author:  t68 [ Sun Mar 03, 2013 7:17 pm ]
Post subject:  Re: Ccc2013

When will CEMC release the stage 2 cut-off? Looks like a lot people solved S5. Could it be 65 for stage 2?

Author:  Unnamed [ Sun Mar 03, 2013 7:38 pm ]
Post subject:  Re: Ccc2013

How is CEMC going to get over this Computer Judge vs. Human Judge issue?

I know they answered with the whole, 6 s = 1 minute thing, but how about this?

The "slow" S5 solution on http://mmhs.ca/ccc/index.htm gets a 12/15 from a human judge, but a 9/15 from the computer judge.

This doesn't affect me, but someone with a 65 with a 9 for S5 may be prevented from moving on to stage 2 if the cut-off was 66 - 68.

Author:  t68 [ Sun Mar 03, 2013 7:44 pm ]
Post subject:  Re: Ccc2013

On the other side, using online judge has the advantage to prevent careless mistakes. I guess it is hard to say which one was a better option for this year's CCC.

Author:  coolgod [ Sun Mar 03, 2013 7:44 pm ]
Post subject:  Re: Ccc2013

From what I heard they will take most of the high scores and remark it once more on their judge. Ultimately the cutoff scores and final ccc scores should be based on the judge because this would be the fairest.

Author:  t68 [ Sun Mar 03, 2013 7:56 pm ]
Post subject:  Re: Ccc2013

or they could give one cut-off for students without on-line judge since they don't have chance to correct their codes and re-submit, and give a different cut-off for people using on-line judge as they had shorter time limit

they even have the option to remove some test cases in S5 to balance out the differences, I guess. Rolling Eyes

Author:  coolgod [ Sun Mar 03, 2013 8:46 pm ]
Post subject:  Re: Ccc2013

what about people who used the
t68 wrote:

or they could give one cut-off for students without on-line judge since they don't have chance to correct their codes and re-submit, and give a different cut-off for people using on-line judge as they had shorter time limit

they even have the option to remove some test cases in S5 to balance out the differences, I guess. roll
what about people given the online judge without feedback? What about people who's code worked on judge but after remark it dropped? What about people who submitted both?

Author:  A.J [ Mon Mar 04, 2013 1:41 am ]
Post subject:  RE:Ccc2013

Student's with a mark of (typically) > 40 have their submissions remarked by the committee, and then the top 20 submissions are decided based on the scores (there might be 21 - 23 participants invited to move on to Stage 2 if there is a tie for 20th). I suspect that the cutoff will be higher than usual this year (~60 - 65).

Author:  t68 [ Mon Mar 04, 2013 10:21 am ]
Post subject:  Re: Ccc2013

coolgod wrote:

From what I heard they will take most of the high scores and remark it once more on their judge. Ultimately the cutoff scores and final ccc scores should be based on the judge because this would be the fairest.


People (without online judge) did not even know this 6s limit. One would use a completely different algorithm for 6s vs. 1min. It is not reasonable to change the time limit rule for them at all (post contest). It is clearly about CEMC's reputation and ethics.

For people with online judge, I am not sure that they knew this 6s time limit up front. If yes, two groups of students were writing this contest with different instructions.

For a national contest like this, this is not a desired outcome. Maybe they could invite more than 20 students this year to make it fair. Very Happy

Author:  Halls McSmurfin [ Mon Mar 04, 2013 4:48 pm ]
Post subject:  RE:Ccc2013

Where does the 6s runtime limit come from? S5 has a 5s runtime limit.

Author:  t68 [ Mon Mar 04, 2013 5:27 pm ]
Post subject:  Re: RE:Ccc2013

Halls McSmurfin @ Mon Mar 04, 2013 4:48 pm wrote:
Where does the 6s runtime limit come from? S5 has a 5s runtime limit.


well, close enough compared with 1min. Smile

Author:  clogfeed [ Wed Mar 20, 2013 11:38 am ]
Post subject:  Re: Ccc2013

The CCC webpage was updated! They've announced when they're going to post the official results [mar 28].

Author:  nullptr [ Thu Mar 28, 2013 5:12 pm ]
Post subject:  Re: Ccc2013

Looks like they changed it to midnight, March 28.

Author:  coolgod [ Thu Mar 28, 2013 7:58 pm ]
Post subject:  Re: Ccc2013

maybe at midnight it will be changed to april 2 lol.

Author:  Unnamed [ Thu Mar 28, 2013 11:12 pm ]
Post subject:  Re: Ccc2013

What timezone are they in? it's 12:12 EST here and still no results Sad

Author:  nullptr [ Thu Mar 28, 2013 11:14 pm ]
Post subject:  Re: Ccc2013

Unnamed @ Thu Mar 28, 2013 11:12 pm wrote:
What timezone are they in? it's 12:12 EST here and still no results Sad


They're in Waterloo so it's midnight there too. I guess they're just late.

Author:  crossley7 [ Thu Mar 28, 2013 11:36 pm ]
Post subject:  RE:Ccc2013

They tend to be late. Don't be impatient. It will likely be don at some point on the next business day so either sometime in the next 24 hours or you may have to wait until Monday

Author:  coolgod [ Thu Mar 28, 2013 11:37 pm ]
Post subject:  Re: Ccc2013

you mean Tuesday Laughing

Author:  Unnamed [ Thu Mar 28, 2013 11:44 pm ]
Post subject:  Re: Ccc2013

Looks like its 9 in the morning Monday...

Author:  coolgod [ Thu Mar 28, 2013 11:49 pm ]
Post subject:  Re: Ccc2013

Unnamed wrote:

Looks like its 9 in the morning Monday...

Then you realize it's April fools day on Monday!

Author:  linuxp [ Fri Mar 29, 2013 12:37 am ]
Post subject:  RE:Ccc2013

March 29 1:20 am

congrats if you are 71-75
Highest cutoff in ccc history

Author:  Unnamed [ Fri Mar 29, 2013 10:06 am ]
Post subject:  Re: RE:Ccc2013

linuxp @ Fri Mar 29, 2013 12:37 am wrote:
March 29 1:20 am

congrats if you are 71-75
Highest cutoff in ccc history


niiiiiiiccce

Author:  nullptr [ Sat Mar 30, 2013 1:14 pm ]
Post subject:  Re: Ccc2013

The Stage 2 invitees were released, and I'm one of them! Very Happy Looks like the cutoff was 72, which is really high -- you had to get everything right except the last S5 test cases.

Author:  Halls McSmurfin [ Sat Mar 30, 2013 8:20 pm ]
Post subject:  Re: Ccc2013

nullptr @ Sat Mar 30, 2013 1:14 pm wrote:
The Stage 2 invitees were released, and I'm one of them! Very Happy Looks like the cutoff was 72, which is really high -- you had to get everything right except the last S5 test cases.


Grats dude but you don't have to get everything right except for the last S5 test cases to make stage 2.


: