好了

#include<bits/stdc++.h>
using namespace std;
struct stu{
    string name;
    string pd;
    string email;
}user[10001];
int main(){
    string e;
    cin>>e;
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>user[i].name>>user[i].pd>>user[i].email;
    }
    bool f=0;
    for(int i=1;i<=n;i++){
        if(user[i].email==e){
            string s=user[i].pd;
            for(int j=0;j<s.length();j++){
                if(s[j]>='A'&&s[j]<='Z'){
                    s[j]=s[j]+32;
                }
                else if(s[j]>='a'&&s[j]<='z'){
                    s[j]=s[j]-32;
                }
            }
            user[i].pd=s;
            f=1;
            cout<<user[i].name<< " "<<user[i].pd<<endl;
        }
    }
    if(f==0){
        cout<<"empty";
    }
    return 0;
}