Compilare: user.cpp: In function ‘int main()’: user.cpp:32:29: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { fread(buff,1,buffs,stdin); ^ user.cpp:33:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.out","w",stdout); ^ user.cpp: In function ‘void read(int&)’: user.cpp:21:57: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pos==buffs) fread(buff,1,buffs,stdin),pos=0; ^ user.cpp:27:57: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pos==buffs) fread(buff,1,buffs,stdin),pos=0; ^