/in/foo.cc: In function 'bool find(std::vector<std::__cxx11::basic_string<char> >&, int, int, std::__cxx11::string)':
/in/foo.cc:9:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(x < 0 || y > s.size() - 1 || x > y) return false;
                 ~~^~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:32:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 for(int i = 0; i < s.size(); i++)
                                ~~^~~~~~~~~~
/in/foo.cc:40:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                     else if(tmp > s[i] && i == s.size() - 1)
                                           ~~^~~~~~~~~~~~~~~