Compilare: main.cpp: In function 'int main()': main.cpp:26:40: warning: narrowing conversion of 'g[y].std::vector<_Tp, _Alloc>::size<arc, std::allocator<arc> >()' from 'std::vector<arc>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] g[x].push_back({y,g[y].size()}); ~~~~~~~~~^~ main.cpp:27:42: warning: narrowing conversion of '(g[x].std::vector<_Tp, _Alloc>::size<arc, std::allocator<arc> >() - 1ul)' from 'std::vector<arc>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] g[y].push_back({x,g[x].size()-1}); ~~~~~~~~~~~^~ main.cpp:59:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=start[ciclu[k]];j<g[ciclu[k]].size();j++){ ~^~~~~~~~~~~~~~~~~~~