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Code-snippets for lambdaheads meetings

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Octocat-spinner-32 99-haskell-problems
Octocat-spinner-32 BWT
Octocat-spinner-32 CodingChallenges
Octocat-spinner-32 Crop
Octocat-spinner-32 README.md
README.md

Here will be all of ε/2's code for lambdaheads meeting

2012-02-19: Crop:

from the ccc2010: the task to solve is to get numbers of an array according to a path.

99-haskell-problems

are just some finger exercises for not loosing grasp of haskell

Coding Challenges

inspired by hop I want to introduce coding challenges to Lambdaheads

Cryptoanalysis 101:

Inspired by a question I answered on stackoverflow.com: One knows the easiest of cryptographic ciphers to break is the "Ceasar-Cipher" it works just by transposition of letters. The way to break it is to analyze the number of occurences of a letter in a text and compare it to a frequency table of the guessed language the text is written in. write a function to decipher the following text by use of frequency analysis

  • the following text is written in english:
    LIVITCSWPIYVEWHEVSRIQMXLEYVEOIEWHRXEXIPFEMVEWHKVSTYLXZIXLIKI
    IXPIJVSZEYPERRGERIMWQLMGLMXQERIWGPSRIHMXQEREKIETXMJTPRGEVEKE
    ITREWHEXXLEXXMZITWAWSQWXSWEXTVEPMRXRSJGSTVRIEYVIEXCVMUIMWERG
    MIWXMJMGCSMWXSJOMIQXLIVIQIVIXQSVSTWHKPEGARCSXRWIEVSWIIBXVIZM
    XFSJXLIKEGAEWHEPSWYSWIWIEVXLISXLIVXLIRGEPIRQIVIIBGIIHMWYPFLE
    VHEWHYPSRRFQMXLEPPXLIECCIEVEWGISJKTVWMRLIHYSPHXLIQIMYLXSJXLI
    MWRIGXQEROIVFVIZEVAEKPIEWHXEAMWYEPPXLMWYRMWXSGSWRMHIVEXMSWMG
    STPHLEVHPFKPEZINTCMXIVJSVLMRSCMWMSWVIRCIGXMWYMX
    
  • the frequency table for the english language is given by:
    ['E', 'T', 'A', 'O', 'I', 'N', 'S', 'H', 'R', 'D', 'L', 'C', 'U'
    ,'M', 'W', 'F', 'G', 'Y', 'P', 'B', 'V', 'K', 'X', 'J', 'Q', 'Z']
    
  • the result should be - as frequency analysis is not a real good tool:
    RENEMYSODEUNTOLTNSHEWIARTUNTKETOLHATAEDBTINTOLFNSMURAPEAREFE
    EADEGNSPTUDTHHCTHEIO WRICRIAWTHEOCDSHELIAWTHTFETMAIGMDHCTNTF
    TEMHTOLTAARTAAIPEMOVOSWOASOTAMNTDIHAHSGCSMNHETUNETAYNIJEIOTH
    CIEOAIGICYSIOASGKIEWARENEWENEAWSNSMOLFDTCVHYSAHOETNSOEEXANEP
    IABSGAREFTCVTOLTDSOUSOEOETNARESARENAREHCTDEHWENEEXCEELIOUDBR
    TNLTOLUDSHHBWIARTDDARETYYETNTOCESGFMNOIHRELUSDLAREWEIURASGAR
    EIOHECAWTHKENBNEPTNVTFDETOLATVIOUTDDARIOUHIOASCSOHILENTAISOI
    CSMDLRTNLDBFDTPEQMYIAENGSNRIHSYIOISONEHYECAIOUIA
    
    • the real result is to be deciphered by rot13!
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