说明：  用C语言异或实现简单文件加密/解密，输入的文件名和需要处理的文件名必须一致，解密密码和加密密码必须一致，不然会是乱码
(XOR C language to achieve a simple file encryption/decryption, enter the file name and the file name must be consistent with the need to deal with decryption password and encryption password must be the same, or will be garbled)