foo.cc: In function 'int main()':
foo.cc:77:25: error: lvalue required as left operand of assignment
   if(int(i/pow(10,n-1))=8)
                         ^
foo.cc:47:7: warning: unused variable 'j' [-Wunused-variable]
  ll i,j,m;
       ^
foo.cc:47:9: warning: unused variable 'm' [-Wunused-variable]
  ll i,j,m;
         ^

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