/in/foo.cc: In function 'int main()':
/in/foo.cc:131:21: warning: unused variable 'next' [-Wunused-variable]
  131 |                 int next = (p == w) ? childTowards(w, B) : par_[p][0];
      |                     ^~~~
/in/foo.cc:93:32: warning: unused variable 'dy' [-Wunused-variable]
   93 |         ll dx = d0[A] - d0[w], dy = d0[B] - d0[w];
      |                                ^~