How can I compare objects of two different classes?

Question

I want to make a program where you can input some random names, then in the next few lines input father > son/daughter . Then the program will search for the father from the first input.

Example:

mia ana
shane > ana

Output will be:

ana < shane

This is the program I made (note anak =child; ayah =father; nama =name):

using namespace std;

class status { 
public:
string ayah, anak1, anak2, anak3;
status (const string& inayah="", const string& inanak1="", const string& inanak2="", const string& inanak3="") : ayah(inayah), anak1(inanak1), anak2(inanak2), anak3(anak3){}
};

class populasi {
string nama1, nama2, nama3, nama4, nama5, nama6;
public:
populasi (const string& innama1="",const string& innama2="",const string& innama3="", const string& innama4="",const string& innama5="",const string& innama6="")
: nama1(innama1), nama2(innama2), nama3(innama3), nama4(innama4), nama5(innama5), nama6(innama6){}



void cek(const status& x)
{
    if( x.anak1() == nama1() ) cout << x.anak1() << " < " << x.ayah() << endl;
    if( x.anak1() == nama2() ) cout << x.anak1() << " < " << x.ayah() << endl;
    if( x.anak1() == nama3() ) cout << x.anak1() << " < " << x.ayah() << endl;
    if( x.anak1() == nama4() ) cout << x.anak1() << " < " << x.ayah() << endl;
    if( x.anak1() == nama5() ) cout << x.anak1() << " < " << x.ayah() << endl;
    if( x.anak1() == nama6() ) cout << x.anak1() << " < " << x.ayah() << endl;

    if( x.anak2 == nama1() ) cout << x.anak2() << " < " << x.ayah() << endl;
    if( x.anak2 == nama2() ) cout << x.anak2() << " < " << x.ayah() << endl;
    if( x.anak2 == nama3() ) cout << x.anak2() << " < " << x.ayah() << endl;
    if( x.anak2 == nama4() ) cout << x.anak2() << " < " << x.ayah() << endl;
    if( x.anak2 == nama5() ) cout << x.anak2() << " < " << x.ayah() << endl;
    if( x.anak2 == nama6() ) cout << x.anak2() << " < " << x.ayah() << endl;

    if( x.anak3 == nama1() ) cout << x.anak3() << " < " << x.ayah() << endl;
    if( x.anak3 == nama2() ) cout << x.anak3() << " < " << x.ayah() << endl;
    if( x.anak3 == nama3() ) cout << x.anak3() << " < " << x.ayah() << endl;
    if( x.anak3 == nama4() ) cout << x.anak3() << " < " << x.ayah() << endl;
    if( x.anak3 == nama5() ) cout << x.anak3() << " < " << x.ayah() << endl;
    if( x.anak3 == nama6() ) cout << x.anak3() << " < " << x.ayah() << endl;
    };  
};

 int main()
 {  
string nama1, nama2, nama3, nama4, nama5, nama6;
fscanf ( stdin, " %s %s %s %s %s %s", &nama1, &nama2, &nama3, &nama4, &nama5, &nama6); 
populasi a (nama1, nama2, nama3, nama4, nama5, nama6);

string ayah, anak1, anak2, anak3;
fscanf ( stdin, " %s > %s %s %s", &ayah, &anak1, &anak2, &anak3); 
status b ( ayah, anak1, anak2, anak3);

fscanf ( stdin, " %s > %s %s %s", &ayah, &anak1, &anak2, &anak3); 
status c ( ayah, anak1, anak2, anak3);

fscanf ( stdin, " %s > %s %s %s", &ayah, &anak1, &anak2, &anak3); 
status d ( ayah, anak1, anak2, anak3);

fscanf ( stdin, " %s > %s %s %s", &ayah, &anak1, &anak2, &anak3); 
status e ( ayah, anak1, anak2, anak3);

fscanf ( stdin, " %s > %s %s %s", &ayah, &anak1, &anak2, &anak3); 
status f ( ayah, anak1, anak2, anak3);

fscanf ( stdin, " %s > %s %s %s", &ayah, &anak1, &anak2, &anak3); 
status g ( ayah, anak1, anak2, anak3);

a.cek(b);
a.cek(c);
a.cek(d);
a.cek(e);
a.cek(f);
a.cek(g);
return 0;
 }

Answer 1

Sadly, you're really going about this in a very "C" style, and missing out on the C++ Standard Library's facilities for parsing input, storing text, and associative containers (that let you store values assocated with "keys" then find them later by specifying the same "key").

Given each person only has one type of data associated with them - their name - there's no need for or benefit from a user-defined class in this program. The std::string class can easily store their name. Your classes stored multiple names, but the C++ standard library containers are better able to do this.

#include <sstream>
#include <iostream>
#include <map>

int main()
{
     std::string first_line;
     if (!getline(std::cin, line))
     {
          std::cerr << "failed to read a line of names\n";
          return 1;
     }

     // read and remember father/child relationships...
     typedef std::map<std::string, std::string> Map;
     Map child_to_father;
     std::string father, child;
     char c = '>';
     while (iss >> father >> c && c == '>' && iss >> child)
         child_to_father[child] = father;
     if (!is.eof() || is.bad() || c != '>')
     {
         std::cerr << "error reading 'father > child' line\n";
         return 1;
     }

     // now report the matches for names on the first line...
     std::istringstream iss(first_line);
     while (iss >> child)
     {
          Map::const_iterator i = child_to_father.find(name);
          if (i != child_to_father.end())
               std::cout << child << " < " << father << '\n';
     }
}