Eroare de compilare: user.cpp: In function 'int compar(double, double)': user.cpp:53: error: call of overloaded 'abs(double)' is ambiguous /usr/include/stdlib.h:691: note: candidates are: int abs(int) /usr/include/c++/4.2/cstdlib:174: note: long long int __gnu_cxx::abs(long long int) /usr/include/c++/4.2/cstdlib:143: note: long int std::abs(long int) user.cpp: In function 'void rezolva()': user.cpp:87: error: 'sqrt' was not declared in this scope