/in/foo.cc: In function 'int dfs(int)':
/in/foo.cc:26:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[x].size();i++)
              ~^~~~~~~~~~~~
/in/foo.cc: In function 'int dfs2(int, int)':
/in/foo.cc:34:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[x].size();i++)
              ~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:52:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<g[now].size();i++) 
               ~^~~~~~~~~~~~~~
/in/foo.cc:68:27: warning: unused variable 'temp' [-Wunused-variable]
    int timenow=0,cur=s[i],temp=ans[mid[i]];
                           ^~~~