Question

Please look at this code (and forgive the lack of knowledge). It outputs errors that I couldn’t solve. I need to declare a vector of elements of struct C,but I need the number of elements be i (a input of type int).

I also tried others approaches but in all of them I received an error (cannot convert C to int,etc). How can I do this?

# include < iostream > using std::cout; using std::cin; using std::endl;  # include < vector > using std::vector;  struct C{     int cor;     vector<int>cores;      };      void LerVector( vector< C> &array ) ;  int main () {      int n;     bool done=false;         bool don=false;     vector<C>cidade;     int i;       while(!done){     cout<<'Entre o número de cidades '<<endl;     cin>>n;     if(n>500)     {         cout<<endl;         cout<<'O número máximo é 500'<<endl; } else done=true; } n--; while(!don){ cout<<'Entre o número de confederações'<<endl; cin>>i; if(i>100){ cout<<endl; cout<<'Número máximo de 100 cidades'<<endl;  } else {   LerVector(  cidade) ;  don=true; } }       cin.get();     return 0; } //resolve...  void LerVector( vector< C> &array )    {      for ( size_t i = 0; i < array.size(); i++ )        cin>>array[i];    } // end function inputVector  

Answer 1

Let’s try with an explanation 🙂

cin >> array[i]; 

That tries to extract from cin into an object of struct C. Well, so it needs an operator>> that actually does that work:

istream & operator>>(istream &is, C &c) {     is >> c.cor; // or into whatever member      return is; } 

In addition, as another one mentioned, you have to actually add the elements to the vector first:

while(!don){     cout<<'Entre o número de confederações'<<endl;     .... } else {     cidade.resize(i); // resize to i elements     LerVector(cidade);     don = true; } 

For the next time, please format the text (correct indent it). It was hard for me to step through it 🙂