Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:12:31: 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:32:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(j=0;j<sol[i].size();j++) g<<sol[i][j]<<" ";g<<'\n';} ^