不会看这

#include <bits/stdc++.h>
using namespace std;
string s,k;
int len;
int main(){
cin>>k;
len=k.size();
for(int i=0;i<=len-1;i++)
if(k[i]>='a' and k[i]<='z')
k[i]=k[i]-32;

cin>>s;
for(int i=0;i<=s.size()-1;i++){
	if(s[i]>='a' and 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' and 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;

}