Compilare: user.cpp: In function ‘double faec(double, double, double, double, double&, double&, double&)’: user.cpp:30: warning: no return statement in function returning non-void user.cpp: In function ‘double solve()’: user.cpp:56: warning: comparison between signed and unsigned integer expressions user.cpp:59: warning: comparison between signed and unsigned integer expressions user.cpp:75: warning: comparison between signed and unsigned integer expressions