Compilare: user.cpp: In function ‘long long int copy(long long int*, long long int*)’: user.cpp:7:11: warning: no return statement in function returning non-void [-Wreturn-type] a[0]=b[0];} ^ user.cpp: In function ‘long long int add(long long int*, long long int*)’: user.cpp:14:10: warning: no return statement in function returning non-void [-Wreturn-type] a[0]=i-1;} ^ user.cpp: In function ‘int main()’: user.cpp:16:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mult.in","r",stdin); ^ user.cpp:17:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mult.out","w",stdout); ^ user.cpp:19:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld",&n,&k); ^ user.cpp:21:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&v[i]); ^