The pull List implements a stack to implement the push (), top, and pop methods.

[Java]
Package test;
 
Import java. util. Collections list;
 
Public class test2 {
Static topology list <Integer> link = null;
Public static void main (String args []) throws Exception {
Link = new shortlist <Integer> ();
Push (1 );
Int d = top ();
System. out. println (d );
Pop ();
Pop ();


}
Static boolean push (int I ){
Link. addFirst (I );
Return true;
}
Static int top (){
Int get = 0;
Try {
Get = link. getFirst ();
} Catch (Exception e) {System. out. println ("no data ");}
Return get;
}
Static boolean pop (){
Try {
Link. removeFirst ();
} Catch (Exception e ){
System. out. println ("no data ");
Return false;
}
Return true;
}
}