foo.cc: In function 'int main()':
foo.cc:9:10: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
  for(int j;j<jj;j++)
          ^
foo.cc:31:8: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<cnt<<endl;
        ^~~
foo.cc:11:11: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
   for(int i;i<ii;i++)
           ^

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。