Data Structures and Algorithm Analysis - Computer Science at ...

104 Chap. 4 Lists, Stacks, and Queues/** Linked list implementation */class LList implements List {private Link head;// Pointer to list headerprivate Link tail;// Pointer to last elementprotected Link curr; // Access to current elementint cnt;// Size of list/** Constructors */LList(int size) { this(); } // Constructor -- Ignore sizeLList() {curr = tail = head = new Link(null); // Create headercnt = 0;}/** Remove all elements */public void clear() {head.setNext(null);// Drop access to linkscurr = tail = head = new Link(null); // Create headercnt = 0;}/** Insert "it" at current position */public void insert(E it) {curr.setNext(new Link(it, curr.next()));if (tail == curr) tail = curr.next(); // New tailcnt++;}/** Append "it" to list */public void append(E it) {tail = tail.setNext(new Link(it, null));cnt++;}/** Remove and return current element */public E remove() {if (curr.next() == null) return null; // Nothing to removeE it = curr.next().element();// Remember valueif (tail == curr.next()) tail = curr; // Removed lastcurr.setNext(curr.next().next()); // Remove from listcnt--;// Decrement countreturn it;// Return value}/** Set curr at list start */public void moveToStart(){ curr = head; }Figure 4.8 A linked list implementation.