vigenere.cpp

Vigenere实验

// vigenere.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "iostream.h"
#include "string.h"
#define max 50

int main(int argc, char* argv[])
{
	int i,j,k,n;
	char ch[max];
	char letter[max][26];
	char in[max];
	cout<<"请输入密钥:"<<endl;
	gets(ch);
//	for(i=0;i<(int)strlen(ch);i++)
//		cout<<ch[i]<<i<<endl;
	n=(int)strlen(ch);

   cout<<"置换表如下:"<<endl;
   for(i=0;i<=n;i++)
   {
	for(j=0;j<26;j++)
	{
		letter[0][j]=97+j;
		letter[i+1][j]=(ch[i]+j-97)%26+97;
		cout<<letter[i][j]<<" ";
	}

	cout<<endl;
   }

   cout<<"请输入明文:"<<endl;
   gets(in);
   for(i=0,k=0;i<(int)strlen(in);i++,k++)
   {
	   j=k;
	   if(in[i]!=32)
	   {
		   j=j%n+1;
		   in[i]=letter[j][in[i]-97];
	   }
	   else k--;
   }
   cout<<"密文为:"<<endl;
   for(i=0;i<(int)strlen(in);i++)
   {
	   cout<<in[i];
   }

   cout<<endl;
    
	return 0;
}