/in/foo.cc: In function 'void bfs()':
/in/foo.cc:123:5: error: 'que' was not declared in this scope
  123 |     que[head] = ed;
      |     ^~~
/in/foo.cc:127:20: error: 'link' was not declared in this scope
  127 |         for (per = link[u]; per; per = per->next) {
      |                    ^~~~