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ELCS - Easy Longest Common Substring |
In this problem, a string only consists of lowercase letters.
Substring, is a consecutive sequence of characters occurrences at least once in a string.
Common substring means a substring of two strings.
After getting TLE on LCS and LCS2, lqp18_31 felt really depressed. So he came up with an interesting idea. He want to modify the definition of LCS and call it ELCS.
ELCS: for two given strings s1[0..n-1] and s2[0..m-1], the ELCS of them is a string p[0..k-1] k <= min(n, m) so that s1[i] = s2[i] = p[i] (for 0 <= i < k) and s1[k] != s2[k] or k == n or k == m.
Now your task is easy.
You are given N strings and Q queries.
Each query consists two integers a and b. You must answer the length of the ELCS of the a-th string and b-th string.
Input
First line consists one integer N.
Next N lines consist N strings.
Next line consists one integer Q.
Next Q lines consist two integers a and b. (0 <= a, b < N)
30% of the test data: N <= 100 Q <= 10000, length(string[i]) <= 100
100% of the test data: the number of total characters <= 500000, N <= 100000, Q <= 100000.
Output
Q lines. Each line consists the length of the ELCS of the a-th string and b-th string.
Example
Input: 5 dy ljq lqp ws jzt 3 0 1 1 2 0 2 Output: 0 1 0
Added by: | 刘启鹏 |
Date: | 2010-05-18 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: NODEJS OBJC PERL6 SQLITE VB.NET |
Resource: | my own problem |
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2016-10-18 23:12:49 Jaber Ahmed
i m using longest common substring approach. Bt got WA.complexity 0(m*n).any other algorithm to solve this problem.please suggest me. |
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2015-09-05 23:52:16 Grzegorz Graczyk
Very important hint for this task: Cin causes cout to flush by default. And time limit in this task is not enough for 100000 flushes. Last edit: 2015-09-06 00:21:16 |
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2010-11-26 01:19:19 Alca
Robbin_Karp is really easy to get an AC. Last edit: 2010-11-27 00:30:34 |
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2010-08-16 07:51:28 ymGXX
Hash algorithm is very simple. Last edit: 2010-09-17 01:57:08 |
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2010-07-08 09:11:05 [Rampage] Blue.Mary
Er, building suffix array (without RMQ ST)takes ~1 second. Maybe hashing is the only way to pass. (Isn't this kind of problem very silly?) Edit: (by [Trichromatic]XilinX) Yes, it's very silly :) RE: hashing is NOT the only way to pass :) Re: (by [Trichromatic]XilinX) Yes, thinking about the essence of suffix tree lead you to the easier algorithm... Last edit: 2010-07-09 14:30:17 |
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2010-06-14 01:09:04 anon
Is there an upper bound for length(string[i]) in 100% of cases? The only one I can infer from the problem statement is 500000 Reply:max{length(string[i])}<=5*10^5 Last edit: 2010-06-14 04:44:27 |
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2010-05-18 23:42:38 Anshu Saurabh
N is always less than 100?? Reply: N <= 100000 Last edit: 2010-05-18 23:44:10 |
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2010-05-18 23:42:38 Damir Ferizovic
It would be better without those percentages. Just make bounds for N , Q , and len. Reply: :) Last edit: 2010-05-19 20:21:48 |
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2010-05-18 23:42:38 Kinan Sarmini
Can you please check the tests? I asserted every single line of the code, nothing is out of bounds everything seems normal, but still SIGSEGV... Reply: 30% of the testdata : N<=100 It doesn't mean that 100% of the testdata N<=100 Last edit: 2010-05-18 12:50:20 |
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2010-05-18 23:42:38 hosam samy
does the first line contain one or two integers ? Reply : One. See the input format. :) Last edit: 2010-05-18 12:23:56 |