/in/foo.cc: In function 'int hsh(int)':
/in/foo.cc:10:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0; i<t[x].size(); i++)
                ~^~~~~~~~~~~~
/in/foo.cc:14:12: error: 's' was not declared in this scope
   sz[x] += s[v]; 
            ^
/in/foo.cc:18:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0; i<h.size(); i++) ansx = (ansx + (h[i]+1)*(i+1))%100000007;
                ~^~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:38:15: error: 'dfs' was not declared in this scope
   dfs(root, -1);
               ^
/in/foo.cc:42:6: warning: unused variable 'num' [-Wunused-variable]
  int num = 1;
      ^~~