/in/foo.cc: In function 'bool init()':
/in/foo.cc:73:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   bool tgt = nodes[i].z + r >= h;
              ~~~~~~~~~~~~~~~^~~~
/in/foo.cc: In function 'bool bfs()':
/in/foo.cc:100:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (nodes[i].z + r >= h)
        ~~~~~~~~~~~~~~~^~~~