Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:24:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<graph[element].size() && !found;i++) ^ user.cpp: In function ‘int main()’: user.cpp:51:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<visited.size();i++) ^ user.cpp:54:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<visited.size();i++) ^