大佬帮忙看看为什么第一题不能通过😭 #include<iostream> #include<vector> using namespace std; int main() {     int n;     string k,v;     vector<string> key;     vector<string> val;     cin>>n;     for(int i=0;i<n+1;i++)     {         int flag=0;         cin>>k>>v;         for(int j=0;j<key.size();j++)             if(key[j]==k)             {                 cout<<key[j]<<" "<<val[j]<<endl;                 val[j]=v;                 flag=1;                 i--;                 break;             }         if(flag==0)             if(i==n)             {                 cout<<key[0]<<" "<<val[0]<<endl;                 key.erase(key.begin());                 val.erase(val.begin());                 i--;             }             key.push_back(k);             val.push_back(v);     }     return 0; }