array list aid in the implementation of methods add and remove assuming that no array expansion is necessarymethods add and remove can be performed in ( timefor they simply involve adding or removing the last element of the array list moreoverthe array list associated with has elements (the element at index is place-holderif we use an extendable array that grows and shrinks for the implementation of the array list (section and exercise - )the space used by the array-list representation of complete binary tree with nodes is (nand operations add and remove take ( amortized time java implementation of complete binary tree we represent the complete binary tree adt in interface completebinarytree shown in code fragment we provide java class arraylistcompletebinarytree that implements the completebinarytree interface with an array list and supports methods add and remove in ( time in code fragments code fragment interface completebinarytree for complete binary tree code fragment class arraylistcompletebinarytree implementing interface completebinarytree using