/in/foo.cc: In function 'int main()':
/in/foo.cc:135:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  135 |         for (int t = 0; t < stack_copy.size(); ++t) {
      |                         ~~^~~~~~~~~~~~~~~~~~~
/in/foo.cc:138:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |             int next_l = (t+1 < stack_copy.size()) ? stack_copy[t+1].first : (i+1);
      |                           ~~~~^~~~~~~~~~~~~~~~~~~