비밀키/나휘동

~cpp 
#include <iostream>  
#include <fstream>  
using namespace std;  
  
void main()  
{  
        char filename[10];  
        cout << "파��� ������ : ";  
        cin >> filename;  
        ifstream fin(filename);  
        ofstream fout("decode.txt");  
          
        char key;  
        cout << "������키 : ";  
        cin >> key;  
  
        cout << "������������������..."<< endl;  
  
        char ch;  
        while( !fin.eof() ){  
                ch = fin.get();  
                ch -= key;//���호화  
                fout << ch;  
                cout << ch;  
        }  
        cout << endl;  
        fin.close();  
        fout.close();  
}