Compilare: user.cpp: In function ‘int ciur(const int&)’: user.cpp:32:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( register int i = 1; i < primes.size( ); ++i ) { ^ user.cpp: In function ‘int main()’: user.cpp:49:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( f, "%d", &N ); ^