/in/foo.cc: In function 'std::vector<std::pair<unsigned int, int> >::iterator ser(int)':
/in/foo.cc:30:95: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(iter=hash_step[ha_in%MOD].begin();iter!=hash_step[ha_in%MOD].end();iter++) if(iter->first==ha_in) break;
                                                                                    ~~~~~~~~~~~^~~~~~~
/in/foo.cc: In function 'int zero(const std::vector<int>&)':
/in/foo.cc:36:12: warning: 'i' is used uninitialized in this function [-Wuninitialized]
  while(in[i]!=0) i++;
            ^
/in/foo.cc: In function 'void rebfs()':
/in/foo.cc:36:12: warning: 'i' is used uninitialized in this function [-Wuninitialized]
  while(in[i]!=0) i++;
            ^
/in/foo.cc:35:6: note: 'i' was declared here
  int i;
      ^
/in/foo.cc: In function 'void bfs()':
/in/foo.cc:36:12: warning: 'i' is used uninitialized in this function [-Wuninitialized]
  while(in[i]!=0) i++;
            ^
/in/foo.cc:35:6: note: 'i' was declared here
  int i;
      ^