Compilare: main.cpp: In function 'void euler(int)': main.cpp:34:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=x[csp].t;i<x[csp].e.size();++i) ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:60:44: warning: narrowing conversion of 'x.std::vector<_Tp, _Alloc>::operator[]<adat, std::allocator<adat> >(((std::vector<adat>::size_type)b)).adat::e.std::vector<_Tp, _Alloc>::size<el, std::allocator<el> >()' from 'std::vector<el>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] x[a].e.push_back({b,x[b].e.size(),0}); ~~~~~~~~~~~^~ main.cpp:61:46: warning: narrowing conversion of '(x.std::vector<_Tp, _Alloc>::operator[]<adat, std::allocator<adat> >(((std::vector<adat>::size_type)a)).adat::e.std::vector<_Tp, _Alloc>::size<el, std::allocator<el> >() - 1ul)' from 'std::vector<el>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] x[b].e.push_back({a,x[a].e.size()-1,0}); ~~~~~~~~~~~~~^~ main.cpp:65:46: warning: narrowing conversion of '(x.std::vector<_Tp, _Alloc>::operator[]<adat, std::allocator<adat> >(((std::vector<adat>::size_type)b)).adat::e.std::vector<_Tp, _Alloc>::size<el, std::allocator<el> >() + 1ul)' from 'std::vector<el>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] x[a].e.push_back({b,x[b].e.size()+1,0}); ~~~~~~~~~~~~~^~ main.cpp:66:46: warning: narrowing conversion of '(x.std::vector<_Tp, _Alloc>::operator[]<adat, std::allocator<adat> >(((std::vector<adat>::size_type)a)).adat::e.std::vector<_Tp, _Alloc>::size<el, std::allocator<el> >() - 1ul)' from 'std::vector<el>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] x[b].e.push_back({a,x[a].e.size()-1,0}); ~~~~~~~~~~~~~^~