二叉树的实现-Huffman树-摘自数据结构实现java版本（个人笔记整理）

//树节点的实现

package tree;import java.util.Iterator;import java.util.LinkedList;import java.util.Stack;public class BinTreeNode {private Object data;private int height;private int size;private BinTreeNode lChild;private BinTreeNode rChild;public BinTreeNode(){this(null);}public BinTreeNode(Object data){this.data = data;}private BinTreeNode parent;public Object getData() {return data;}public void setData(Object data) {this.data = data;}public int getHeight() {return height;}public void setHeight(int height) {this.height = height;}public int getSize() {return size;}public void setSize(int size) {this.size = size;}public BinTreeNode getlChild() {return lChild;}public BinTreeNode setlChild(BinTreeNode lChild) {BinTreeNode oldLeftChild = getlChild();if(hasLChild()) oldLeftChild.sever();if(lChild!=null){lChild.sever();this.setlChild(lChild);lChild.setParent(this);this.upDateHeight();this.upDateSize();}return oldLeftChild;}public BinTreeNode getrChild() {return rChild;}public BinTreeNode setrChild(BinTreeNode rChild) {BinTreeNode oldRightChild = getrChild();if(hasRightChild())oldRightChild.sever();if(rChild!=null){rChild.sever();rChild.setParent(this);this.setrChild(rChild);}return oldRightChild;}public BinTreeNode getParent() {return parent;}public void setParent(BinTreeNode parent) {this.parent = parent;}public boolean hasParent(){return parent!=null;}public boolean hasLChild(){return lChild!=null;}public boolean hasRightChild(){return rChild!=null;}public boolean isLeaf(){return getlChild()==null&&getrChild()==null;}public boolean isRightChild(){return hasParent()&& getParent().getrChild()==this;}public boolean isLeftChild(){return hasParent()&&getParent().getrChild()==this;}public void upDateHeight(){int newHeight =0;if(hasRightChild())newHeight=Math.max(newHeight, getrChild().getHeight()+1);if(hasLChild())newHeight = Math.max(newHeight, getlChild().getHeight()+1);if(newHeight==getHeight())return;setHeight(newHeight);//向上递归更新if(hasParent())getParent().upDateHeight();}public void upDateSize(){size = 1;if(hasLChild())size+=getlChild().getSize();if(hasRightChild())size+=getrChild().getSize();if(hasParent())getParent().upDateSize();}//断开与父节点的关系public void sever(){if(getParent()==null)return;if(isRightChild()){getParent().setrChild(null);}else{getParent().setlChild(null);}getParent().upDateHeight();getParent().upDateSize();setParent(null);}public Iterator PreOrder(){LinkedList list = new LinkedList<BinTreeNode>();PreOrderTravelRecusion(this,list);return list.iterator();}//前续递归算法private void PreOrderTravelRecusion(BinTreeNode root,LinkedList list){if(root==null) return; list.add(root); if(hasLChild())PreOrderTravelRecusion(getlChild(), list); if(hasRightChild())PreOrderTravelRecusion(getrChild(), list);}//前续非递归算法private void PreOrderTravel(BinTreeNode root,LinkedList list){if(root==null) return;Stack stack =new Stack<BinTreeNode>();BinTreeNode p = root;while(p!=null){while(p!=null){list.add(p);if(p.hasRightChild())stack.push(p.getrChild());p=p.getlChild();}if(!stack.isEmpty())p=(BinTreeNode) stack.pop();}}//中序非递归算法private void inOrderTravel(BinTreeNode root,LinkedList list){BinTreeNode p =root;if(root==null)return;Stack stack = new Stack<BinTreeNode>();while(!stack.isEmpty()||p!=null){while(p!=null){stack.push(p);p = p.getlChild();}if(!stack.isEmpty()){p = (BinTreeNode) stack.pop();list.add(p);p=p.getrChild();}}}//后续遍历非递归private void postOrderTravel(BinTreeNode root,LinkedList list){if(root == null) return;BinTreeNode p = root;Stack stack = new Stack<BinTreeNode>();while(!stack.isEmpty()||p!=null){stack.push(p);if(p.hasLChild()){p=p.getlChild();}else{p = p.getrChild();}}if(!stack.isEmpty()){p = (BinTreeNode) stack.pop();list.add(p);}BinTreeNode top = (BinTreeNode) stack.peek();if(!stack.isEmpty()&&top.getrChild()==p){p = (BinTreeNode) stack.pop();list.add(p);}if(!stack.isEmpty()){p = top.getrChild();}else{p=null;}}}

//Huffman节点

package tree;public class HuffmanTreeNode extends BinTreeNode{private int weight;private String code="";public HuffmanTreeNode(int weight){this(weight,null);}public HuffmanTreeNode(int weight,Object data){super(data);this.weight=weight;}public int getWeight() {return weight;}public void setWeight(int weight) {this.weight = weight;}public String getCode() {return code;}public void setCode(String code) {this.code = code;}public HuffmanTreeNode getParent(){return (HuffmanTreeNode) super.getParent();}public HuffmanTreeNode getlChild(){return (HuffmanTreeNode) super.getlChild();}public HuffmanTreeNode getrChild(){return (HuffmanTreeNode) super.getrChild();}}

//haffman的构造

package tree;


import java.util.ArrayList;
import java.util.List;


public class HuffmanTreeBuilder {
public static HuffmanTreeNode buildHuffmanTree(HuffmanTreeNode[] nodes){
int length = nodes.length;
List list = new ArrayList<HuffmanTreeNode>();
if(length<2){return nodes[0];}
for(int i=0;i<length;i++){
insertIntoList(nodes[i], list);
}
for(int i=0;i<length;i++){
HuffmanTreeNode min1 = (HuffmanTreeNode) list.remove(list.size()-1);
HuffmanTreeNode min2 = (HuffmanTreeNode) list.remove(list.size()-1);
HuffmanTreeNode newNode = new HuffmanTreeNode(min1.getWeight()+min2.getWeight());
newNode.setlChild(min1);
newNode.setrChild(min2);
min1.setParent(newNode);
min2.setParent(newNode);
insertIntoList(newNode, list);
}
return (HuffmanTreeNode) list.get(0);


}

//按照大小顺序插入链表中 ，具体的链表自己实现
public static void insertIntoList(HuffmanTreeNode node,List< HuffmanTreeNode> list){
for(int i=0;i<list.size();i++)
if(node.getWeight()>list.get(i).getWeight()){
list.add(node);
}
}
public static void generatorHuffmanTree(HuffmanTreeNode root){
if(root == null) return;
if(root.hasParent()){
if(root.isLeftChild()) root.setCode(root.getParent().getCode()+"0");
if(root.isRightChild())root.setCode(root.getParent().getCode()+"1");
}
generatorHuffmanTree(root.getlChild());
generatorHuffmanTree(root.getlChild());
}
}