Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:56:61: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++poz == DIM) fread(buff, 1, DIM, stdin), poz = 0; ^ user.cpp:60:61: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++poz == DIM) fread(buff, 1, DIM, stdin), poz = 0; ^ user.cpp: In function ‘int main()’: user.cpp:66:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.in", "r", stdin); ^ user.cpp:67:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.out", "w", stdout); ^