foo.cc: In function 'int main()':
foo.cc:64:11: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     cout<<ans<<endl;
           ^~~
foo.cc:29:14: warning: 'next' may be used uninitialized in this function [-Wmaybe-uninitialized]
     while(now!=n)
           ~~~^~~

自豪的采用 HydroJudger 进行评测(github.com/hydro-dev/HydroJudger)

{"receive":"2020-05-29T11:38:12.078Z","handle":"2020-05-29T11:38:12.078Z","cache_start":"2020-05-29T11:38:15.388Z","read_cases":"2020-05-29T11:38:19.446Z","judge":"2020-05-29T11:38:19.446Z","done":"2020-05-29T11:38:23.133Z"}