题解

#include <bits/stdc++.h>
using namespace std;
string s,k;

int main()
{
cin>>k;
int len=k.size();
for(int i=0;i<=len-1;i++)
{
if(k[i]>='a' && k[i]<='z') k[i]=k[i]-32;
}
cin>>s;
for(int i=0;i<=s.size()-1;i++)
{
if(s[i]>='a' && s[i]<='z')
{
int x=s[i]-'a';
int y=k[i%len]-'A';
s[i]=(x-y+26)%26+'a';
}
else if(s[i]>='A' && s[i]<='Z')
{
int x=s[i]-'A';
int y=k[i%len]-'A';
s[i]=(x-y+26)%26+'A';
}
}
for(int i=0;i<=s.size()-1;++i)
{
cout<<s[i];
}
return 0;
}