aa.rar_Caesar_world

#include <stdio.h> # include<iostream.h> void main() { char M[100]; char C[100]; int k,i; cout<<"\n***加密***\n"<<endl; cout<<"请输入明文M(注意不要输入空白串)"<<endl; gets(M); cout<<"请输入您的密钥(必需是整数):"<<endl; cin>>k; for(i=0;M[i]!='\0';i++) C[i]=(M[i]-'a'+k)%26+'a'; C[i]='\0'; cout<<"所得的凯撒密码为:"<<endl; cout<<C<<endl; cout<<"\n***解密***\n"<<endl; cout<<"您的凯撒密码:"<<C<<endl; cout<<"你的密钥是："<<k<<endl; for(i=0;C[i]!='\0';i++) M[i]=(C[i]-'a'-k+26*(k/26+1))%26+'a'; M[i]='\0'; cout<<"你的明文为:"<<M<<endl; }