Compilare: user.cpp: In function ‘int main()’: user.cpp:58:34: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘std::vector<std::__cxx11::basic_string<char> >::size_type {aka long unsigned int}’ [-Wformat=] fprintf(fout,"%d\n" ,v.size()); ^ user.cpp:59:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i++) { ^ user.cpp:19:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%s " ,str + 1); ^