Compilare: main.cpp: In function 'void bfs()': main.cpp:21:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[nod].size();i++){ ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:40:36: warning: narrowing conversion of 'g[y].std::vector<_Tp, _Alloc>::size<numar, std::allocator<numar> >()' from 'std::vector<numar>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] g[x].push_back({y,g[y].size()}); ~~~~~~~~~^~ main.cpp:41:38: warning: narrowing conversion of '(g[x].std::vector<_Tp, _Alloc>::size<numar, std::allocator<numar> >() - 1ul)' from 'std::vector<numar>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] g[y].push_back({x,g[x].size()-1}); ~~~~~~~~~~~^~