Not_So_Great's blog

Can someone help me with this problem C1. Message Transmission Error (hard version)?
By Not_So_Great, history, 21 month(s) ago, In English

I have solved the easy version of the problem. But I have no idea how to solve this one. Do I require any new algorithms? Can someone please help me solve this problem?

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21 month(s) ago, hide # |
 
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Learn pattern searching algorithms like Z function, KMP, etc. I used Z function to solve this question.

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    21 month(s) ago, hide # ^ |
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    Can you explain a bit more in detail on how to solve this after learning pattern matching algorithms?

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      21 month(s) ago, hide # ^ |
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      The problem after this will turn into "for string $$$s$$$ of length $$$n$$$, find any index $$$i$$$ ($$$2 \le i \le n$$$) such as $$$s(i, n) = s(1, n-i+1)$$$ and $$$i \le n-i+1$$$".

      (Here, $$$s(i, j)$$$ means a contiguous substring of $$$s$$$ from index $$$i$$$ to index $$$j$$$, inclusively).

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