foo.cc: In lambda function:
foo.cc:20:59: error: invalid use of member function ‘double student::zs()’ (did you forget the ‘()’ ?)
   20 |         sort(st+1,st+n+1,[](student x,student y){return x.zs>y.zs;});
      |                                                         ~~^~
      |                                                             ()
foo.cc:20:64: error: invalid use of member function ‘double student::zs()’ (did you forget the ‘()’ ?)
   20 |         sort(st+1,st+n+1,[](student x,student y){return x.zs>y.zs;});
      |                                                              ~~^~
      |                                                                  ()