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

Sec. 4.1 Lists 109/** Singly linked list node with freelist support */class Link {private E element; // Value for this nodeprivate Link next; // Point to next node in list/** Constructors */Link(E it, Link nextval){ element = it; next = nextval; }Link(Link nextval) { next = nextval; }/** Get and set methods */Link next() { return next; }Link setNext(Link nxtval) { return next = nxtval; }E element() { return element; }E setElement(E it) { return element = it; }/** Extensions to support freelists */static Link freelist = null; // Freelist for the class/** @return A new link */static Link get(E it, Link nextval) {if (freelist == null)return new Link(it, nextval); // Get from "new"Link temp = freelist;// Get from freelistfreelist = freelist.next();temp.setElement(it);temp.setNext(nextval);return temp;}}/** Return a link to the freelist */void release() {element = null; // Drop reference to the elementnext = freelist;freelist = this;}Figure 4.11 Implementation for the Link class with a freelist. The staticdeclaration for member freelist means that all Link class objects share thesame freelist pointer variable instead of each object storing its own copy.