Accepted
/in/foo.cc: In function 'void dfs(int)': /in/foo.cc:15:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) //走不下去就是叶子结点 ~^~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int)': /in/foo.cc:15:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) //走不下去就是叶子结点 ~^~~~~~~~~~~~