foo.cc: In function 'int main()':
foo.cc:11:20: 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 (int i = 0; i <= a.size() - b.size(); )
      |                  ~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:14:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |   for (int j = 0; j < b.size(); j++)
      |                   ~~^~~~~~~~~~

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