Compilare: user.cpp: In function ‘int euler(int)’: user.cpp:37:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:67:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ans.size() - 1; ++i) ^