Remove useless code & add log
Remove useless code & add log

bluebore/bfs,lylei/dfs,linyvxiang/dfs,linyvxiang/dfs,yvxiang/coverage_for_bfs,bluebore/dfs,yvxiang/dfs,bluebore/bfs,bluebore/bfs,baidu/bfs,myawan/bfs-1,yvxiang/dfs,yvxiang/dfs,yvxiang/coverage_for_bfs,baidu/bfs,bluebore/dfs,00k/ToyDFS,yvxiang/coverage_for_bfs,linyvxiang/dfs,lylei/dfs,bluebore/dfs,yvxiang/coverage_for_bfs,myawan/bfs-1,baidu/bfs,00k/ToyDFS,lylei/dfs,myawan/bfs-1,yvxiang/dfs,lylei/dfs,myawan/bfs-1,baidu/bfs