foo.cc: In function 'int main()':
foo.cc:40:30: 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]
   40 |                 if (a.size() == n / 2 || b.size() == n / 2)
      |                     ~~~~~~~~~^~~~~~~~
foo.cc:40:51: warning: comparison of integer expressions of different signedness: 'std::priority_queue<int, std::vector<int>, std::less<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   40 |                 if (a.size() == n / 2 || b.size() == n / 2)
      |                                          ~~~~~~~~~^~~~~~~~

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