foo.cc: In function 'void TreeDP(int, int)':
foo.cc:56:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int z = 0; z < edge[x].size(); z++)
                  ~~^~~~~~~~~~~~~~~~
foo.cc:53:6: warning: unused variable 't1' [-Wunused-variable]
  int t1 = 1, t2 = 0;
      ^~
foo.cc:53:14: warning: unused variable 't2' [-Wunused-variable]
  int t1 = 1, t2 = 0;
              ^~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。