Eroare de compilare: user.cpp: In function ‘bool cmp(const std::pair<double, double>&, const std::pair<double, double>&)’: user.cpp:27:28: error: invalid initialization of reference of type ‘std::pair<double, double>&’ from expression of type ‘const std::pair<double, double>’ return det(pct[1], a, b)>0; ^ user.cpp:20:8: error: in passing argument 2 of ‘double det(std::pair<double, double>&, std::pair<double, double>&, std::pair<double, double>&)’ double det(pair<double, double> &a, pair<double, double> &b, pair<double, double> &c) ^ user.cpp:28:1: warning: control reaches end of non-void function [-Wreturn-type] } ^