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Talk:Vigenère cipher/Cryptanalysis: Difference between revisions
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::::: I went to do some changes of my own yesterday, but was stymied by my not having a C++0x compiler handy enough to stick with it; codepad.org hasn't upgraded yet. I'd make the further change of using std::vector for frequency()'s buffer, but making it a class member variable. I'd have frequency() take a reference as an argument, and pass a reference as its return value. And there were some other dependent changes, but that completely avoids the reallocation issue; frequency()'s buffer gets re-written from scratch each call through, so there's no need to clear and reinitialize separately. Just pass double(26) into its constructor as part of the class's constructor. --[[User:Short Circuit|Michael Mol]] 20:42, 22 June 2011 (UTC)
:::::: Alright. That's a reasonable explanation. (Except for class to struct, which just bugs me.) I think the C++0x features used here are somewhat minor at the moment, but as I mentioned before, the array class might be appropriate. I can try and make the suggested changes. [[User:MagiMaster|MagiMaster]] 21:11, 22 June 2011 (UTC)
:::::: Ok. I made frequency() use a member variable, and changed several vectors to arrays. I also added a typedef since array<pair<char, double>, 26> is kind of long and is used several times. (That also happened to remove most instances of ">>".) The targets and sortedTargets could also be of the FreqArray type for consistency, but they wouldn't be using the extra char info, so I left them as double arrays for simplicity. [[User:MagiMaster|MagiMaster]] 21:35, 22 June 2011 (UTC)
:::: Actually, using the C++0x array class might be appropriate here. It's size is a compile-time constant, but it can still be sorted and everything. (Actually, I'm not sure, but I think you can sort a normal array too, but the array class is safer.) [[User:MagiMaster|MagiMaster]] 19:52, 21 June 2011 (UTC)
== Promote to full task? ==
Anyone have any reasons to not promote this? [[User:MagiMaster|MagiMaster]] 14:15, 20 July 2011 (UTC)
: Sounds reasonable to me, now that there are a number of solutions. We probably ought to start putting our solutions in as well so that newcomers to the problem can check their answers, and it's also reasonable to encourage people to use code from [[Vigenère cipher]] for the final decrypt once the key is derived; no point in duplicating needlessly. –[[User:Dkf|Donal Fellows]] 10:42, 29 July 2011 (UTC)
:: Isn't the code from the [[Vigenère cipher]] task a little short to be decrypted autonomously? (I haven't actually tried, so I'm not sure.) Also, I think the answer for the code given should be obviously right, but I'd like to hear other's opinions on this. I didn't want to include the answer so that people could treat it as a puzzle if they wanted. (Would putting the answer on a separate page be ok?) [[User:MagiMaster|MagiMaster]] 18:54, 29 July 2011 (UTC)
::: "Using code from" probably only means doing the output for this task once the key is determined. I'd prefer leaving the output option open to the implementions, for example in the C code I only listed most probable keys found, but didn't do any actual decoding because only a human can have a final say in the correctness of key and deciphered text. --[[User:Ledrug|Ledrug]] 19:03, 29 July 2011 (UTC)
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