Compilare: user.cpp: In function ‘int cer3(int)’: user.cpp:27:19: warning: variable ‘elem’ set but not used [-Wunused-but-set-variable] int st=1,dr=n,elem; ^~~~ user.cpp:39:1: warning: no return statement in function returning non-void [-Wreturn-type] }; ^ user.cpp: In function ‘int main()’: user.cpp:42:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cautbin.in","r",stdin); ^ user.cpp:43:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cautbin.out","w",stdout); ^