foo.cc: In function 'int main()':
foo.cc:81:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i=0;i<path.size();i++)
             ~^~~~~~~~~~~~
foo.cc:78:8: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
     dfs(pa,x,y,0);
     ~~~^~~~~~~~~~
foo.cc:78:8: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]

正在同步测试数据，请稍后
自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。