Compilare: user.cpp: In function ‘int main()’: user.cpp:17:36: 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:18:38: 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:19:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld\n",&T); ^ user.cpp:22:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld%ld\n",&x,&y); ^ user.cpp: In function ‘int Euclid(long int, long int)’: user.cpp:13:12: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] return r; ^