implementing queue with generic linked list round robin schedulers double-ended queues the deque abstract data type implementing deque exercises java datastructures net stacks stack is collection of objects that are inserted and removed according to the lastin first-out (lifoprinciple objects can be inserted into stack at any timebut only the most recently inserted (that is"last"object can be removed at any time the name "stackis derived from the metaphor of stack of plates in spring-loadedcafeteria plate dispenser in this casethe fundamental operations involve the "pushingand "poppingof plates on the stack when we need new plate from the dispenserwe "popthe top plate off the stackand when we add platewe "pushit