foo.cc: In function 'int Index(std::string, std::string, int)':
foo.cc:9:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |  while (i < s.size() && j < t.size())
      |         ~~^~~~~~~~~~
foo.cc:9:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |  while (i < s.size() && j < t.size())
      |                         ~~^~~~~~~~~~
foo.cc:16:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  if (j == t.size())
      |      ~~^~~~~~~~~~~

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