시간 제한 | 메모리 제한 | 제출 | 정답 | 맞힌 사람 | 정답 비율 |
---|---|---|---|---|---|
1 초 | 1024 MB | 53 | 29 | 25 | 55.556% |
Hill encryption (devised by mathematician Lester S. Hill in 1929) is a technique that makes use of matrices and modular arithmetic. It is ideally used with an alphabet that has a prime number of characters, so we'll use the $37$ character alphabet A
, B
, $\ldots$, Z
, 0
, 1
, $\ldots$, 9
, and the space character. The steps involved are the following:
A
$\rightarrow 0$, B
$\rightarrow 1$, $\ldots$, (space)
$ \rightarrow 36$. If the plaintext is ATTACK AT DAWN
this becomes $$0\ 19\ 19\ 0\ 2\ 10\ 36\ 0\ 19\ 36\ 3\ 0\ 22\ 13$$.FPLSFA4SUK2W9K3
.This method can be generalized to work with any $n \times n$ encryption matrix in which case the initial plaintext is broken up into vectors of length $n$. For this problem you will be given an encryption matrix and a plaintext and must compute the corresponding ciphertext.
Input begins with a line containing a positive integer $n \leq 10$ indicating the size of the matrix and the vectors to use in the encryption. After this are $n$ lines each containing $n$ non-negative integers specifying the encryption matrix. After this is a single line containing the plaintext consisting only of characters in the $37$-character alphabet specified above.
Output the corresponding ciphertext on a single line.
3 30 1 9 4 23 7 5 9 13 ATTACK AT DAWN
FPLSFA4SUK2W9K3
6 26 11 23 14 13 16 6 7 32 4 29 29 26 19 30 10 30 11 6 28 23 5 24 23 6 24 1 27 24 20 13 9 32 18 20 18 MY HOVERCRAFT IS FULL OF EELS
W4QVBO0NJG5 Y76H5A6XHR11BV670Z
ICPC > Regionals > North America > East Central North America Regional > 2020 East Central Regional Contest E번