#include <stdio.h>
char enc(char ch)
{
if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z'))
{
if(ch>='a')
{
ch+=('a'+13-ch)*2-1;
}
else
{
ch+=('A'+13-ch)*2-1;
}
}
return ch;
}
int main()
{
char s[20]="123abcmz8ABMZN";
int i=0;
while(*(s+i))
{
s[i]=enc(s[i]);
i++;
}
printf("加密後:%s\n",s);
i=0;
while(*(s+i))
{
s[i]=enc(s[i]);
i++;
}
printf("原 文:%s\n",s);
return 0;
}