/in/foo.cc: In function 'void initDepths(int, int)':
/in/foo.cc:12:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int v = 0; v < G[node].size(); v++){
                     ~~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int changeState(int, bool)':
/in/foo.cc:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < G[num].size(); i++){
                     ~~^~~~~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:32:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int v = 0; v < depths[layer].size(); v++){
                     ~~^~~~~~~~~~~~~~~~~~~~~~