加密算法.cpp

此小程序为N栏栅加密算法程序的一种

//学校：武汉理工大学
//qq号：297416605
//姓名：万艳良
#include<iostream.h>
void main()
{   
	char exit;
	cout<<"Do you want to exit?(y or n)"<<endl;
	cin>>exit;
	while(exit!='y'||exit=='n')
	{
	char a[50],b;
	int e=0,i=0,m,n,N;

	//加密
	cout<<"please input the Key N:"<<endl;
	cin>>N;
	cout<<"Please input the P-text(ended with the letter @):"<<endl;
	cin>>b;
    a[i]=b;
	i++;
	while(b!='@')
	{ 
		cin>>b;
		if(b=='@')
			a[i]=' ';
		else
		   a[i]=b;
		i++;
	}
	i--;
	//输出密文
	cout<<"the C-text is:"<<endl;
	for(n=0;n<=N-1;n++)
	{
	   for(m=n;m<=i-1;m+=N)
	   {
		 cout<<a[m]<<"";
	   }
	}
	cout<<endl;
    cout<<"Do you want to exit?(y or n)"<<endl;
	cin>>exit;
}
}