vigenere.cpp

vigenere 加密算法以及解密算法

#include <stdio.h>
#include <string.h>


char table[26][26] =
{
'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
'b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a',
'c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b',
'd','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c',
'e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d',
'f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f',
'h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g',
'i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h',
'j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i',
'k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j',
'l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k',
'm','n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l',
'n','o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m',
'o','p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n',
'p','q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o',
'q','r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p',
'r','s','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q',
's','t','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r',
't','u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s',
'u','v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t',
'v','w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u',
'w','x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'x','y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w',
'y','z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x',
'z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y'
} ;
int main()
{
	char plain[100] ;
	char key[100] ;
	char Encode[100] ;
	int  textlen , keylen , i , j , k , t ;
	for(i=0;i<100;i++)
	{
	  plain[i]=0;
	  key[i]=0;
	  Encode[i]=0;
	
	}
	

	i = 0 ; j = 0 ; k = 0 ; t = 0 ;
	printf("请输入密钥:\n") ;
	scanf("%s",key) ;
	keylen = strlen(key) ;
	printf("请输入明文:\n") ;
	scanf("%s" , plain) ;
	textlen = strlen(plain) ;
	for(i=0 ; i<textlen ; i++)
	{
		j = i%keylen ;
		k = key[j]-'a';
		t = plain[i]-'a' ;
		Encode[i] = table[k][t] ;
	}
	printf("密文为:\n%s\n" , Encode) ;   
	/*解密*/
	
	
	
/*	printf("请输入密钥:\n") ;
	scanf("%s",key) ;
	keylen = strlen(key) ;
	printf("请输入密文:\n") ;
	scanf("%s" , Encode) ;
	textlen = strlen(Encode) ;
	
	
	
	for(i=0 ; i<textlen ; i++)
	{
		j = i%keylen ;
		k = key[j]-'a' ;
		for(t =0 ; t<26 ; t++)
		{
			if(table[k][t] == Encode[i]) 
			{
				plain[i] = t+'a' ; 
				break ;
			}
		}
	}
    printf("明文: \n%s\n",plain);

	return 0 ;*/
}