/in/foo.cc: In function 'bool dbfs(std::__cxx11::string, int, std::__cxx11::string, int, int, int)':
/in/foo.cc:147:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < ori.size(); i++)
                    ~~^~~~~~~~~~~~
/in/foo.cc:173:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < ori.size(); i++)
                    ~~^~~~~~~~~~~~
/in/foo.cc: In function 'char direct(Site)':
/in/foo.cc:103:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^