Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:18:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ^ user.cpp:27:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:66:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<solutii.size();i++) ^