Compilare: user.cpp: In function ‘HN& prod(HN&, const long long int&)’: user.cpp:108:5: warning: reference to local variable ‘temp’ returned [-Wreturn-local-addr] HN temp; ^ user.cpp: In function ‘int main()’: user.cpp:132:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tort.in", "r", stdin); ^ user.cpp:133:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tort.out", "w", stdout); ^ user.cpp:135:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &a, &b); ^