Compilare: user.cpp: In function ‘bool safe(std::vector<sheap>&, int)’: user.cpp:30:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos>=heap.size()) ^ user.cpp: In member function ‘bool dijkstra::add_or_update(sheap)’: user.cpp:143:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (upd.node>=vpos.size()) ^ user.cpp: In function ‘int main()’: user.cpp:200:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<muchii[now].size();i++) ^