Mathematical and Physical Journal
for High Schools
Issued by the MATFUND Foundation
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# Problem I. 170. (November 2007)

I. 170. Nervous John works as a system administrator for a company. One day he accidentally deleted a program used by his boss, Forgetful Fred. The purpose of that program was to put digital signatures at the end of e-mails: Fred chose a word (signature'') depending on the content of the mail, wrote it at the end, then used the program to generate a code'' from the signature, and wrote the code also at the end of the mail. In order to make sure that a mail has been signed by Fred, he only had to enter the signature into his program and check if the generated code was the same.

Unfortunately, John could recover only 3 e-mails with the following signatures/codes:

Nemes/wiqiRd
kemence/igriqioh
TROMBITA/EXMFQSVXP

Your task is to help John and reconstruct Fred's program. The input should be a signature, then the code, as the output, should be written on the screen. The source code (i170.pas, i170.cpp, ...) should be submitted.

(10 pont)

Deadline expired on December 17, 2007.

Sorry, the solution is available only in Hungarian. Google translation

Megoldás. A feladatból a kódolás pontos menete, és a kód végén álló plusz karakter kiszámítási módja nem található ki egyértelműen. A versenyzők többsége mégis ügyes és egyszerű kódolást adott. Az utolsó karakterre több lehetséges megoldás is született. A két mintamegoldás: Véges Márton budapesti versenyző (i170.cpp) és Póta Kristóf egri tanuló (i170.pas) munkája.

### Statistics:

 11 students sent a solution. 10 points: Adrián Patrik, Englert Péter, Földes Imre, Póta Kristóf, Véges Márton. 9 points: Horváth 135 Loránd, Molnár Gábor, Pap 987 Dávid, Wolf Attila. 7 points: 1 student. 5 points: 1 student.

Problems in Information Technology of KöMaL, November 2007