Compilare: main.cpp: In function 'int dfs(int, int)': main.cpp:34:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = firstE[curr]; i < sys[curr].size(); i++){ ~~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int bfs()': main.cpp:65:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sys[curr].size(); i++){ ~~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:103:44: warning: narrowing conversion of 'sys[v].std::vector<_Tp, _Alloc>::size<edg, std::allocator<edg> >()' from 'std::vector<edg>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] sys[u].push_back({v, c, sys[v].size()}); ~~~~~~~~~~~^~ main.cpp:105:46: warning: narrowing conversion of '(sys[u].std::vector<_Tp, _Alloc>::size<edg, std::allocator<edg> >() - 1ul)' from 'std::vector<edg>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] sys[v].push_back({u, 0, sys[u].size()-1}); ~~~~~~~~~~~~~^~