[BOJ] 1032.명령 프롬프트 [구현] - c++

#include <iostream>
#include <string>
#include <vector>
using namespace std;
int N;
string s;
vector<string> sentence;

int main() {
    cin>>N;
    cin>>s;
    if(N==1) {cout<<s; return 0;}
    for(int i=1;i<N;i++)
    {
        string tmp ="";
        cin>>tmp;
        sentence.push_back(tmp);
    }
  
    for(int j=0;j<N-1;j++){
        for(int i=0;i<s.size();i++)
        {
            if(s[i]!=sentence[j][i]) s[i]='?';
        }
    }
    
    cout<<s;
}