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Discussion of Problem 1485. Football and Lie

very easy
Posted by Maryin Dima 11 Oct 2006 20:55
It was very easy.
Backtracking(перебор с возвратом)
Re: very easy
Posted by svr 15 Oct 2006 13:03
I think that it is hard problem and has exp(n) complexity.
If remove psevdopractic decoration it is to solve a system
boolean equation of 100 unknows  Xi with type of Xi^Xj=0;
(NotXi)^Xj=0;(NotXi)^(NotXj)=0. Amount of equation is near 10000. Thus we have easy problem for weak tests and very hard problem for detailed test. This situation was brightly shoun for identical Ships problems.Programmers should create code working on all possible tests in prescribed range of variables.
Re: very easy
Posted by svr 16 Oct 2006 22:59
Now I am also having Ac(0.031) by using backtracking. I have applied this method to boolean problem not to Graf. But I fear that we all will lost our submits if problem will be rejudged.
Re: very easy
Posted by Orenburg SU 7 16 Oct 2006 23:23
In worst case in complexy is O(n^2)
Re: very easy
Posted by Denis Koshman 22 Aug 2008 14:25
Yes, it's O(N^2). And resembles another problem of this type: 1382
Re: very easy
Posted by Stefan 26 May 2009 15:04
does transitive closure algorithm work here?
Re: very easy
Posted by bsu.mmf.team 9 Jun 2016 23:53
Just a standard 2-SAT problem.