#include<iostream>
#include<cstring>
using namespace std;
void decrypt();//解密函数
void encrypt();//加密函数
void main()
{  
cout<<" ____________________________________________"<<endl;
cout<<"|                                            |"<<endl;
cout<<"|         多表代换密码Playfair的实现         |"<<endl;
cout<<"|              欢迎使用本程序                |"<<endl;
cout<<"|____________________________________________|"<<endl;
......................