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test 30????????  gooooooogol  1285. Thread in a Hyperspace  11 Jun 2018 18:21  1 

Problem 1285 "Thread in a Hyperspace" has been rejudged  Vladimir Yakovlev (USU)  1285. Thread in a Hyperspace  3 May 2018 17:24  3 
New tests have been added to the problem which exploit a common mistake when using acos function. Hint: try to calculate acos(sqrt(3.0) * sqrt(3.0)  4.0) in your programming language. 269 authors (58%) with accepted solutions have been challenged. Why is this a mistake? How to modify the solution to avoid the mistake? Who knows? OK, just need to add a clamp for acos' arg. 
same as 1075  ssor96  1285. Thread in a Hyperspace  2 Mar 2018 18:00  1 
this task is the same as 1075, but with a different number of dimensions(it doesn't really matter) 
WA #1 Why???  B@R5uk  1285. Thread in a Hyperspace  21 Dec 2017 22:27  3 
I submitted some algo which on my computer gives correct result for sample input given in problem statement and I got WA in test #1. Then I tried this code: public class Problem_1285 { public static void main(String[] args) { System.out.println("1.00"); } } ...and got the same WA #1. What's going on??? Seems like test #1 is not the sample test Seems like test #1 is not the sample test It is often the case. 
Your tests are incorrect.  XraY  1285. Thread in a Hyperspace  1 Oct 2012 12:58  2 
There are a lot of tests (i know two: 4 and 9), in which r <= 0. Please, change it! Tests with r = 0 are fixed. Thank you. 
WA #26  SS(Batyr' Olexandr)  1285. Thread in a Hyperspace  7 Nov 2011 17:31  2 
WA #26 SS(Batyr' Olexandr) 27 Jul 2011 15:50 1075 with same algorithm have got AC. Can somebody help me? I need some tests or hints... Is this test correct? 1000 0 0 0 0 0 0 0 1000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 999 answer: 3138.51 i get that,too and i wa 25 
WA#16  TheDreamCatcher  1285. Thread in a Hyperspace  17 Jun 2011 16:18  2 
WA#16 TheDreamCatcher 4 Dec 2010 10:50 Re: WA#16 molphys fti UFU (Ekaterinburg) 17 Jun 2011 16:18 the same reason as WA #4 of 1075 
to Judges.  ACM.Tolstobrov_Anatoliy[Ivanovo SPU]  1285. Thread in a Hyperspace  29 Sep 2010 17:48  7 
to Judges. ACM.Tolstobrov_Anatoliy[Ivanovo SPU] 4 Jun 2006 13:57 I got WA37 in 1285 and AC on 1075 I use not diffrens algos, only different input type. I think correct add test and for 1075 too. Me too. But I have WA on test #7. Something strange... I agree with you. Two years ago I wrote about 1075: "What is a difference between this problem and problem 1285? I have AC program of 1285 and always get WA Test#4 here." Tests were updated since 2004. But why not to make such updates in both problems simultaneously? IMHO, if you add several tricky test to 1285 then you should add tests of the same structure to 1075 and vice versa. But here the test set of one problem is weaker then another one's. Oh1! I missed a REALLY stupid mistake! Sorry for my complaint! AC now. Edited by author 25.08.2006 21:11 Edited by author 25.08.2006 21:11 I made it here with modified 1075 AC on 1075, WA#19 on 1285 =( maybe some system tests are incorrect? 
Geometrical question  Samsonov Alex [USU]  1285. Thread in a Hyperspace  20 Aug 2009 00:27  2 
Can anybody explain me, where am I wrong? Definitions: ac, ab, bc  corresponding lengths acb  angle between (ca) and (cb) Such code: ... acb = acos((ac*ac + bc*bc  ab*ab) / 2.0 / ac / bc); .. gets AC. Such code: ... double spv(point x1, point x2, point y1, point y2){ int i; double res = 0; for (i=1; i<=n; i++){ res += (x2.coord[i]  x1.coord[i]) * (y2.coord[i]  y1.coord[i]); } return res; } ... acb = acos(spv(c,a,c,b)/ac/bc);... ... gets WA25. I had always thought that these two fragments must yield the same result. Why don't they? me too. If you get WA27, use type double 
To Judges. Tests!  Yermak  1285. Thread in a Hyperspace  8 Oct 2008 17:59  2 
Are you sure that your tests are ok? Does the first test coincide with the example? I have WA1. 
What's wrong? Tests' incorect?  pperm  1285. Thread in a Hyperspace  25 Sep 2007 09:52  4 
Фрагмент кода при проверки лежит ли путь через сферу. Почему то вещественная проверка проходит, а целочисленная нет. хотя в long long все должно влазить. Извините, что на русском, но писать на английском я совсем не могу) int i; long long a=0,b=0; for (i=0;i<maxd;i++) { a+=sqr(p2.x[i]p1.x[i]); b+=(p2.x[i]p1.x[i])*(x[i]p1.x[i]); } if (b<0b>a) return false; //AC double t=(double)b/a; double rr=0; for (i=0;i<maxd;i++) rr+=sqr((p2.x[i]p1.x[i])*t+p1.x[i]x[i]); rr=sqrt(rr); return rr<r; //WA7 long long t=0; for (i=0;i<maxd;i++) t+=sqr((p2.x[i]p1.x[i])*b+a*p1.x[i]a*x[i]); return r*r*a*a>t; } //В задаче 1075 тоже самое только WA на 12 тесте. Edited by author 31.07.2007 12:53 For example, r=1000, a=8*(1000(1000))^2=32000000. r*r*a*a > MaxLongLongInt. thank you)) Edited by author 25.09.2007 09:29 Tests correct. I AC with Long arithmetic. 
Problem 1285 "Thread in a hyperspace". Tests have been updated ()  Vladimir Yakovlev (USU)  1285. Thread in a Hyperspace  26 May 2006 13:09  1 
Tests 5, 9 and 10 were incorrect > fixed. Tests were too weak > some new tests have been added. Problem has been rejudged. 
Some clarifications (+)  Michael Rybak (accepted@ukr.net)  1285. Thread in a Hyperspace  10 Feb 2006 04:03  1 
Although problem statement says r > 0 and AC, BC > r, 1. It's possible that r == 0 2. It's possible that AC == r or BC == r 
I think tests are incorrect. Check it please.  Borisov Nikita  1285. Thread in a Hyperspace  5 Jan 2006 06:03  1 
I' ve got Crash (FLT_DIVIDE_BY_ZERO). I added one condition: If r = 0 then WriteLn(d:0:2) and get AC. But in the task we can read: "The radius R is integer positive number" 
Give me some Tests  VALERO  1285. Thread in a Hyperspace  23 Mar 2005 19:59  2 
1 2 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 Answer 5.14 
Why R in test is nonnegative, but R must be positive?  root1  1285. Thread in a Hyperspace  3 Jun 2004 14:16  1 
