Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:22:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<graf[k].size(); i++) ^ user.cpp:27:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<graf[k].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:55:23: warning: ‘start’ may be used uninitialized in this function [-Wmaybe-uninitialized] dfs(start, -1); ^