/in/foo.cc: In function 'int main()':
/in/foo.cc:34:23: warning: comparison of integer expressions of different signedness: 'std::priority_queue<int, std::vector<int>, std::greater<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   34 |         if (pq.size() < k) {
      |             ~~~~~~~~~~^~~