Compilare: main.cpp: In function 'int main()': main.cpp:57:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<double, double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 57 | for(i=1;i<vp.size();i++){ | ~^~~~~~~~~~ main.cpp:40:11: warning: unused variable 'j' [-Wunused-variable] 40 | int i,j,nr,n,id; | ^ main.cpp:40:13: warning: unused variable 'nr' [-Wunused-variable] 40 | int i,j,nr,n,id; | ^~ In file included from /usr/include/c++/12.2.1/string:47, from /usr/include/c++/12.2.1/bits/locale_classes.h:40, from /usr/include/c++/12.2.1/bits/ios_base.h:41, from /usr/include/c++/12.2.1/ios:42, from /usr/include/c++/12.2.1/istream:38, from /usr/include/c++/12.2.1/fstream:38, from main.cpp:1: In member function 'constexpr __gnu_cxx::__normal_iterator<_Iterator, _Container> __gnu_cxx::__normal_iterator<_Iterator, _Container>::operator+(difference_type) const [with _Iterator = std::pair<double, double>*; _Container = std::vector<std::pair<double, double> >]', inlined from 'int main()' at main.cpp:52:25: /usr/include/c++/12.2.1/bits/stl_iterator.h:1144:47: warning: 'id' may be used uninitialized [-Wmaybe-uninitialized] 1144 | { return __normal_iterator(_M_current + __n); } | ^~~ main.cpp: In function 'int main()': main.cpp:40:18: note: 'id' was declared here 40 | int i,j,nr,n,id; | ^~