用尽可能少的代码实现DES密码算法的加密、解密功能，可以任意调整算法论数，加密解密在一个程序中都可实现，只需修改flg的值为1或0就可简单开或关加密或解密算法。-With as little as possible code realize DES cipher encryption, decryption function, can adjust the number of algorithms, encryption and decryption in one program can be