Compilare: main.cpp: In function 'int main()': main.cpp:50:32: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::set<int>::size_type {aka long unsigned int}' [-Wformat=] fprintf (fout,"%d",s.size()); ^ main.cpp:26:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&n); ^ main.cpp:29:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&x,&y); ^