/in/foo.cc: In function 'void dp(int)':
/in/foo.cc:12:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<son[x].size();i++)
              ~^~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:38:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i=1;i<=n;i++)
  ^~~
/in/foo.cc:44:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   dp(root);
   ^~