foo.cc: In function 'int main(int, const char**)':
foo.cc:13:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |  for (int i = 0; i < ans.size(); i++) {
      |                  ~~^~~~~~~~~~~~
foo.cc:15:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |   if (i < ans.size() - 1)
      |       ~~^~~~~~~~~~~~~~~~

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