Compilare: user.cpp: In function ‘int main()’: user.cpp:17:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("euclid2.in" , "r" , stdin); ^ user.cpp:18:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("euclid2.out" , "w" , stdout); ^ user.cpp:20:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d" , &T); ^ user.cpp:22:69: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d" , &a , &b) , printf ("%d\n" , Euclid (a , b)); ^