Binary Trees - Data Structures and Algorithm Analysis - page 182

/ ** Huffmantreenodeimplementation:Baseclass * /
publicinterfaceHuffBaseNode<E>{
publicbooleanisLeaf();
publicintweight();

}
/ ** Huffmantreenode:Leafclass * /
classHuffLeafNode<E>implementsHuffBaseNode<E>{
privateEelement; //Elementforthisnode
privateintweight; //Weightforthisnode

/ ** Constructor * /
publicHuffLeafNode(Eel,intwt)
{element=el;weight=wt;}

/ ** @returnTheelementvalue * /
publicEelement(){returnelement;}

/ ** @returnTheweight * /
publicintweight(){returnweight;}

/ ** Returntrue * /
publicbooleanisLeaf(){returntrue;}

}
/ ** Huffmantreenode:Internalclass * /
classHuffInternalNode<E>implementsHuffBaseNode<E>{
privateintweight; //Weight(sumofchildren)
privateHuffBaseNode<E>left;//Pointertoleftchild
privateHuffBaseNode<E>right;//Pointertorightchild

/ ** Constructor * /
publicHuffInternalNode(HuffBaseNode<E>l,
HuffBaseNode<E>r,intwt)
{left=l;right=r;weight=wt;}

/ ** @returnTheleftchild * /
publicHuffBaseNode<E>left(){returnleft;}

/ ** @returnTherightchild * /
publicHuffBaseNode<E>right(){returnright;}

/ ** @returnTheweight * /
publicintweight(){returnweight;}

/ ** Returnfalse * /
publicbooleanisLeaf(){returnfalse;}

}

Figure5.27 Implementation for Huffman tree nodes. Internal nodes and leaf
nodes are represented by separate classes, each derived from an abstract base class.