c++ over load oprator to print variable of clas
ostream& operator<< (ostream& out, graph g) {
for (int i = 0; i < g.size; ++i) {
for (int j = 0; j < g.size; ++j)
out << (g.grph[i][j] ? "true" : "false") << "\t";
out << endl;
}
return out;
}