~cpp
#include <fstream>
#include <iostream>
using namespace std;
int main()
{
ifstream fin("source.txt");
ofstream fout("output.txt");
// ofstream fout2("result.txt");
char a;
int key;
cout << "key 를 력(단,) : ";
cin >> key;
while(fin>>a)
{
fout << (char)((int)a+key);
cout << (char)((int)a+key);
}
cout << " 료..능..\n";
return 0;
}
...메....
반대로....메는 메뿐..
반대로....메는 메뿐..










