/*

* 题目：如果把明文字母按一定顺序排列成矩阵形式，用另一种顺序选择相应的列输出得到密文，如用“china”为秘钥，对”this is

* a book mark“排成矩阵如下：

* t h i s i

* s a b o o

* k m a r k

*/

-/** Topic: If the plaintext letters arranged in a matrix form according to a certain order, in another column in order to select the appropriate output ciphertext, such as using " china"　as the secret key, for " this is* a book mark"　row matrix as follows:* thisi* saboo* kmark* /