Compilare: user.cpp: In function ‘int main()’: user.cpp:14:10: warning: unused variable ‘pi’ [-Wunused-variable] double pi = 4.0 * atan(1.0); ^ user.cpp:9:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tictac.in", "r", stdin); ^ user.cpp:10:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tictac.out", "w", stdout); ^ user.cpp:11:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &t); ^ user.cpp:16:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%lf %lf", &hour, &minutes); ^