What constituted the betrayal?
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И пока в кармане пачка милкиуэйев - значит все не так уж плохо на сегодняшний день
I won't guess if I'm wrong.
Added 2 minutes later
Oh, my bad, Westmarch.
И пока в кармане пачка милкиуэйев - значит все не так уж плохо на сегодняшний день
Added 4 hours and 49 minutes later
Anyway, if no one knows, let Hermit or Ment come up with an answer.
And it's unlikely that anyone here knows.
И пока в кармане пачка милкиуэйев - значит все не так уж плохо на сегодняшний день
Added after 16 hours and 32 minutes
Okay, let me make a wish. It's a very easy riddle.
Stirlitz needs to transmit a 4-bit message to headquarters. Gestapo agents can corrupt any single bit of the transaction. How should he agree with headquarters to transmit information so that the message is guaranteed to be read by headquarters, if the length of the transaction cannot exceed 7 bits?
Gestapo agents can corrupt any single bit of a transaction.
The length of a transaction cannot exceed 7 bits.
If the answer to all questions is "yes", then all four bits should be transmitted one by one, and Alex can change the value of the bits to the opposite and read them. However, on the other hand, it is not necessarily true that the Germans will corrupt this bit; the wording says that they "may"...
"Corrupt" = change a bit to its opposite value?
Added 3 minutes later
"Corrupt" = change a bit to its opposite value?
Can it be broken down into several smaller transactions, so that in total there are 7 bits (or less)?
If the answer to all questions is "yes", then all four bits should be transmitted one by one, and Alex can change the value of the bits to the opposite and read them. Although, on the other hand, it is not a fact that the Germans will necessarily corrupt this bit; the wording says that they "may"...
Added 3 minutes later
Ah, they might not corrupt anything at all...
Ничто не возникает из ничего и ничто не пропадает бесследно.
Если где-то чего-то убудет, то в другом месте добавится.
(Закон сохранения).
Three extra bits should duplicate three of the four main bits. If the duplicates are the same, then the non-duplicated bit is corrupted; otherwise, we look for where the difference lies.
Added 3 minutes later
Ah, there they might not corrupt anything at all...
Okay, let's say we received the message 0011011. How can we tell which bit is corrupted?
Added 1 minute later
Ah, there they might not corrupt anything at all...
In the 5th bit, we write 0 if the first 2 bits are 00 or 01, and 1 if they are 10 or 11.
In the 6th bit, we write 0 if the 3rd and 4th bits are 00 or 01, and 1 if they are 10 or 11.
In the 7th bit, we write 0 if the 5th and 6th bits are 00 or 01, and 1 if they are 10 or 11.
Let's say the message is 1001. We append - 1001101.
If nothing is corrupted, then everything matches.
If the first bit of the message is corrupted, it will be visible because it won't match the 5th bit. At the same time, the 5th bit matches the 7th bit.
And if the 5th bit is corrupted, it won't match the 7th bit. And also not with the first and second.
If the 7th bit is corrupted, it won't match the 5th and 6th bits.
If the 6th bit is corrupted, it won't match the 3rd and 4th and 7th bits.
....
In general, I haven't checked all the options, but there's a chance that this is correct; I couldn't come up with anything better.
Message - first 4 bits.
In the 5th bit, we write 0 if the first 2 are 00 or 01, and 1 if they are 10 or 11.
In the 6th bit, we write 0 if the 3rd and 4th are 00 or 01, and 1 if they are 10 or 11.
In the 7th bit, we write 0 if the 5th and 6th are 00 or 01, and 1 if they are 10 or 11.
Let's say the message is 1001. We append - 1001101.
If nothing is corrupted, everything matches.
If the first bit of the message is corrupted, it will be visible because it won't match the 5th bit. At the same time, the 5th matches the 7th.
And if the 5th bit is corrupted, it won't match the 7th. And also not the first and second.
If the 7th is corrupted, it won't match the 5th and 6th.
If the 6th is corrupted, it won't match the 3rd, 4th, and 7th.
....
In general, I haven't checked all the options, but there's a chance that this is correct; I couldn't come up with anything better.
Let's say he wants to transmit the combination 0101. Then, according to your algorithm, the fifth bit is 0, the sixth is 0, the seventh is 0, and the entire message is 0101000. How can you tell, for example, that this is 0101, where no bit has been corrupted, and not 0001 or 0100, where the second (fourth) bit has been corrupted? After all, for 0001, the combination will be 0001000, and for 0100 - 0100000.