Compilare: user.cpp: In function ‘int main()’: user.cpp:5:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dubi.in","r",stdin); ^ user.cpp:6:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dubi.out","w",stdout); ^ user.cpp:8:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:7:23: warning: ‘bit’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n,i,nr=2000000000,bit,aux; ^~~