位输入的DES 加密解密算法实现 单一CPP实现,其中1.txt用于明文输入,key2.txt用于密钥输入,out2.txt为加密后的密文 与解密后的明文输出-Enter the DES encryption and decryption algorithm to achieve a single CPP, which expressly 1.txt for input, key2.txt for key input, out2.txt for encrypted and decrypted