foo.cc: In function 'void solve(std::string)':
foo.cc:15:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for (int i = 0; i < s.size(); i++)
      |                     ~~^~~~~~~~~~
foo.cc:53:21: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
   53 |             cout << t;
      |                     ^

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