Compilare: user.cpp: In function ‘void write()’: user.cpp:30:50: warning: format ‘%lld’ expects argument of type ‘long long int’, but argument 2 has type ‘int’ [-Wformat=] printf ( "%lld\n", primes[n+1] * primes[n+1] ); ^ user.cpp: In function ‘void read()’: user.cpp:22:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "prim.in", "r", stdin ); ^ user.cpp:23:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d", &n ); ^ user.cpp: In function ‘void write()’: user.cpp:29:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "prim.out", "w", stdout ); ^