/in/foo.cc: In function 'void Mark(int)':
/in/foo.cc:33:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     for(int i = 0; i < G[cur].size(); i++)
      |                    ~~^~~~~~~~~~~~~~~
/in/foo.cc: In function 'bool judge(int)':
/in/foo.cc:41:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     for(int i = 0; i < G[x].size(); i++)
      |                    ~~^~~~~~~~~~~~~