来个map映射一下ok了，z的ascII码122，后面一个是'{',Z是90。注意string的find找不到返回string::npos而不是0判断条件时要注意

#include <string>
#include <map>
#include <vector>

using namespace std;

int main() {
    map<string,string> m ={
        {"abc","2"},
        {"def","3"},
        {"ghi","4"},
        {"jkl","5"},
        {"mno","6"},
        {"pqrs","7"},
        {"tuv","8"},
        {"wxyz","9"},
};
    string str,temp;
    while(cin>>str){
        for(int i = 0;i<str.size();i++){
            if(islower(str[i])){
                for(auto &it:m){
                    if((it.first.find(str[i]))!=string::npos) temp+=it.second;
                }
            }
            else if (isupper(str[i])){
                str[i] = tolower(str[i]);
                if((str[i]+1)!=123) temp+=(str[i]+1);
                else temp+='a';
            }
            else
                temp+=str[i];
            
        }
        cout<<temp<<endl;
        
    }
    
    
    
    
    
}