/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:28:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < numList.size(); ++i) {
                   ~~^~~~~~~~~~~~~~~~
/in/foo.cc:30:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (i != numList.size() - 1) {
        ~~^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:53:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j;
         ^