foo.cc: In function 'int main()':
foo.cc:25:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     while (i < red.size() && j < blue.size())
      |            ~~^~~~~~~~~~~~
foo.cc:25:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     while (i < red.size() && j < blue.size())
      |                              ~~^~~~~~~~~~~~~
foo.cc:33:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |         while (nexti < red.size() && red[nexti] == red[i])
      |                ~~~~~~^~~~~~~~~~~~
foo.cc:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         while (nextj < blue.size() && blue[nextj] == blue[j])
      |                ~~~~~~^~~~~~~~~~~~~

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