Project Euler Forum

Exactly.

aha thanks ,,

Would someone mind to take a look at my code (Python)? I think I have a decent approach but when I execute it I get weird characters (like musical notes, something similar to a telephone...) in the console and even the format gets scrambled. The XOR example works fine and I've been tested some other cases... Thanks.

Hi, i have a little problem with this one ,i missunderstand the problem because english is not my mother tongue ! so if anyone would explain where is the password to encrypt the text !
Thanks very much for your help

Guessing the password is part of the problem. It consists of three lower case characters for example abc, xyz, hex, qwe, etc

stijn263 wrote:Guessing the password is part of the problem. It consists of three lower case characters for example abc, xyz, hex, qwe, etc

Just a question : the password is in the text file ?

No it's not.
There's a single password, that you can use to decrypt the text file (using the procedure described in the problem text, the bitwise xor), that will result in a valid english text.
Solving this problem is about finding the password.

stijn263 wrote:No it's not.
There's a single password, that you can use to decrypt the text file (using the procedure described in the problem text, the bitwise xor), that will result in a valid english text.
Solving this problem is about finding the password.

Thanks for the help !
You said that we have to guess the password ! that's mean that there is not a way to find it ! just try each time a sequence of 3 alphabet ?
this is a little bit strange

Come to think of it:
How many three letter passwords are there?
Would it be too much of a trouble to go over them and find out which one converts the text into a valid English one?
You need only to find out a way to let your program decide if the converted text is a valid English one.

hk wrote:Come to think of it:
How many three letter passwords are there?
Would it be too much of a trouble to go over them and find out which one converts the text into a valid English one?
You need only to find out a way to let your program decide if the converted text is a valid English one.

Thanks so much for the clarification !
last question please because english is not my mother tongue !
English valid text contain only Alphabet ,but there some special characters like ' and " - are there included too.
Thanks so much and sorry if i had bothered you with my question

A valid English text can also contain other characters than [a..z,A..Z], can't it?

hk wrote:A valid English text can also contain other characters than [a..z,A..Z], can't it?

Please execuse multiple question but in english as i know we can write for example : I will = I'll ! or i"ll it's correct right ??

Forget for a moment that English.
Suppose the text should be in your mother tongue.
How would you proceed then?

hk wrote:Forget for a moment that English.
Suppose the text should be in your mother tongue.
How would you proceed then?

sorry for being late to respond !
I think that i would seek for the alphabet in my mother tongue ! and then see if there any sepecial char otherwise it's wrong !

Is this really how you see with one eye if a text is in English or French?
According to you the text:
Kleiner Mann was machst du nun
is perfect French and English and Spanish as well as perfect Italian and perfect Portuguese, which isn't true true because it is German.

@satyres : As hk said, there aren't that many three-letter passwords. This means you could probably do something manually.

satyres,

It does not matter if the text contains special character ( '. ", /, 3, etc.) the same password would be used to encode and decode them.

As far as special characters in the password, the problem states "the encryption key consists of three lower case characters." In the English language, that is generally taken to be from the set {a, b, c, … z}. If the problem intended to allow other characters to be part of the encryption key, it should state that, or this thread would have lots of objections to the phrasing.

As suggested above, one might try all possible three-letter combinations - that will solve the problem - The question then becomes, "how to streamline the process?"

Thanks all for the help ! really appreciate ;
but there is a little missunderstood ! i know that the password containt only 3 alphabet ! the question is how to know that those 3 aplhabet are the good one to decode the text ! should i try every possiblity.
Thanks again and sorry for the missunderstood ! hope not bothering too much.

There are 26*26*26 possible passwords. As a human, if you tried a password, you would immediately be able to tell whether this was correct because the decoded text would become readable English, rather than jibberish.

The point of the program you have to write is to do this step automatically - determine whether a block of text makes sense in English, using your knowledge of how English works.

TripleM wrote:There are 26*26*26 possible passwords. As a human, if you tried a password, you would immediately be able to tell whether this was correct because the decoded text would become readable English, rather than jibberish.

The point of the program you have to write is to do this step automatically - determine whether a block of text makes sense in English, using your knowledge of how English works.

Thanks for the clarification i will do my best !