foo.cc: In function 'void get_state_number(std::string, int)':
foo.cc:11:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |     for (; i < s.length()-2; i++) {
      |            ~~^~~~~~~~~~~~~~
foo.cc:24:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |     if (i == s.length() - 2 && s[i] == 'B' && s[i + 1] == 'A') {
      |         ~~^~~~~~~~~~~~~~~~~

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