Compilare: user.cpp: In member function ‘HN& HN::operator-(const HN&)’: user.cpp:28:6: warning: reference to local variable ‘ans’ returned [-Wreturn-local-addr] HN ans = *this; ^ user.cpp: In member function ‘HN& HN::operator/(const int&)’: user.cpp:41:6: warning: reference to local variable ‘ans’ returned [-Wreturn-local-addr] HN ans; ^ user.cpp: In function ‘int main()’: user.cpp:81:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragonball.in", "r", stdin); ^ user.cpp:82:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragonball.out", "w", stdout); ^ user.cpp:84:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d ", &n, &t); ^ user.cpp: In member function ‘void HN::Read()’: user.cpp:20:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", a+1); ^