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how to prove the answer is NO when k > 20  panyong0202  1669. Universal Word  30 Nov 2014 18:19  1 
I have got ac by return NO when k > 20, but how to prove it? 
What is algo?  IgorKoval(from Pskov)  1669. Universal Word  29 Sep 2013 16:23  2 
simple DP: int leftPos[char][pos] position of char which is left or equal of pos int lastPos[mask] : for substring s[lastPos[mask]..s.length()1] we can get all name of sportman with char which is in mask. =) 
test 70： n == 18 and answer is YES  Orthocenter  1669. Universal Word  8 Mar 2012 13:37  1 

How to avoid TLE  SevenEleven [Tartu U]  1669. Universal Word  20 Aug 2011 19:56  5 
Can M*N*2^(n) dp solution be improved, so that it passes all test? ( Probably it could be M*2^(n)), or it's wrong and I have to think on completely new solution? Yes. It can be easily optimized to O(N*logS*2^N).(S  is the length of the word). But even O(N*S*2^N) solution can pass all tests. Well, my n * s * 2^n solution didn't pass until I added a (as it turned out) curcial optimization. Edited by author 27.07.2009 03:08 My solution is s*2^n ... it runs extremely fast with a very short code :) Edited by author 01.08.2010 16:59 Edited by author 01.08.2010 16:59 
Wonder what's the solutions which runs in 0.1 second?  Gandalf  1669. Universal Word  20 Feb 2010 18:29  1 

Wrong Answer #73  Vanja Petrovic Tankovic  1669. Universal Word  3 May 2009 15:20  3 
I don't print 'NO' if N is large, I check it normally, but I still get WA #73? Whats the trick with this test? Is there a word that is 'YES' for N>18? Edited by author 03.05.2009 00:44 My AC program assumes there is no string with N>18, so debug your code Thanks, I had a silly bug. 
Time Limit Exceeded  Test #14  Varun Sharma  1669. Universal Word  30 Apr 2009 09:29  1 
Hi, For large test cases like n = 18 etc, if the answer is Yes, does that mean that our program will need to test for all the 18 factorial possibilities ? That's like running the loop 10^16 times which is impossible within 3 seconds ! Thanks 
Is n<=8??? (If the word has <300 letters)  Yulia  1669. Universal Word  2 Feb 2009 00:03  5 
NO. there are some pattern that satisfy for n>8 Edited by author 20.12.2008 20:49 Suppose secuence like abcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklmabcdefghjklm etc.. I have WA 70. please tell me is there any test case where n == 18 && answer == "YES"? int test 70 n == 18 and answer is YES ;) 
No subject  vav[14]  1669. Universal Word  26 Dec 2008 14:05  1 
Edited by author 28.12.2008 21:37 Edited by author 28.12.2008 21:38 
New test (+)  Sandro (USU)  1669. Universal Word  21 Dec 2008 22:46  1 
We analysed AC solutions of this problem from online contest and add new test. 3 solutions from contest output wrong answer on it. 
wrong answer #8  Custar  1669. Universal Word  21 Dec 2008 07:29  6 
i don't know why WA in test 8. please help thx very much i can find the mistake. but i don't know how to correct I have faced the same problem. The test 8  WA. On the test: 4 abcabcab The algorithm answers NO i correct it for this problem it must answer YES. i use another algorithm but got WA in test 28. plz. help thx. Why on the test: 4 abcabcab The answer  YES? In the example there is no letter d 
when will these problems add to prob. set?  wFeral  1669. Universal Word  20 Dec 2008 19:38  2 

How many tests are there?  Marginean Ciprian  1669. Universal Word  20 Dec 2008 17:45  1 
