Compilare: user.cpp: In function ‘int main()’: user.cpp:29:30: 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, 220000, stdin); ^ user.cpp: In function ‘void read(long long int&)’: user.cpp:12:124: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] while((buff[pos] < '0' || buff[pos] > '9')&&buff[pos]!='-') if(++pos == 220000) fread(buff, 1, 220000, stdin), pos = 0; ^ user.cpp:18:67: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pos == 220000) fread(buff, 1, 220000, stdin), pos = 0; ^