foo.cc: In function 'int main()':
foo.cc:79:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=1;i<=n;i++)scanf("%d%d%d",&v[i],&u[i],&w[i]);
                          ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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。