/in/foo.cc: In function 'int main()':
/in/foo.cc:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for (int i = 0; i <= a.length(); ++i) {
      |                     ~~^~~~~~~~~~~~~
/in/foo.cc:19:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |         if (i == a.length() || a[i] == ' ') {
      |             ~~^~~~~~~~~~~~~