foo.cc: In function 'int main()':
foo.cc:13:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |  for (int i = 0; i < s.length();)
      |                  ~~^~~~~~~~~~~~
foo.cc:17:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |   for (j = 0; j < t.length();)
      |               ~~^~~~~~~~~~~~
foo.cc:27:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |   if (j == t.length())
      |       ~~^~~~~~~~~~~~~
foo.cc:29:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |    if (i+j <= s.length())
      |        ~~~~^~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务