gomineral04's blog

By gomineral04, 13 years ago, In English

Hello! I am a 24-year-old scholar.

In this round, I solved all problems and the solutions passed system tests, but I failed this Qual.

I got only 2,250 points (150+300+450+600+750) and the 1085th place. -> Standings

I think this round was in intense competition ...

A

In Problem A, we are required to implement carefully. — My solution is O(N log N).

B

In Problem B, we can't use O(N^2) algorithm. — My solution is O(1000^2) with two-dimensional array.

C

Problem C is very nice, but it is difficult for "Problem C".
Getting the improvement for O(nks) is easy, but implementations are slightly complicated for beginners.

--- My solution is O(N log N) with self-balancing binary search tree.

D

In Problem D, we are required to use O(N^2) algorithm for getting palindromic substring. — My solution is O(N^2) with effective palindrome judgment.

E

In Problem E, we are required to notice that "number of use" is important. — My solution is O(N log N) with a lot of sortings.

By the way, I like data structures. Data structures were required by most problems, so I like this round.

  • Vote: I like it
  • -2
  • Vote: I do not like it

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13 years ago, # |
Rev. 3   Vote: I like it +37 Vote: I do not like it

You are my hero! I will always remember you before submitting a problem!

P.S. 128 submits are truly great result

P.P.S. My personal best is +33 and I even thought that it's impossible to accomplish any bigger, but your achivement gives me faith.

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13 years ago, # |
Rev. 2   Vote: I like it +12 Vote: I do not like it

Not that it matters for you anymore but since you are 24 you weren't even allowed to participate (unless your birthday was a couple of days ago, in that case 'happy belated birthday!').

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13 years ago, # |
  Vote: I like it +3 Vote: I do not like it

Problem C may can use simple way with O(n * (k + s)) . Just count every number appear times in every segment(there are k segment), then just like implement. Find the letter you want to delete in which segment , then spend O(s) to find it in the segment. I think it may be work fine with time limited 3s. (Forgive my poor English...)