Accepted
/in/foo.cc: In function 'void Tree::dfs(int)': /in/foo.cc:73:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<son[x].size();i++) ~^~~~~~~~~~~~~~
/in/foo.cc: In function 'void Tree::dfs(int)': /in/foo.cc:73:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<son[x].size();i++) ~^~~~~~~~~~~~~~