树-父节点表示法（java实现）

package com.fcy.dataStruct;import java.util.ArrayList;import java.util.List;class TreeParent<E>{public static class Node<T>{T data;//记录其父节点的位置int parent;public Node(){}public Node(T data){this();this.data=data;}public Node(T data,int parent){this.data=data;this.parent=parent;}public String toString(){return "TreeParent$Node[data]"+data+",parent="+parent+"]";}}private final int DEFAULT_TREE_SIZE=100;private int treeSize=0;//使用一个Node[]数组来记录该树里的所有节点private Node<E>[] nodes;//记录节点数private int nodeNums;//以指定根节点创建树@SuppressWarnings("unchecked")public TreeParent(E data){treeSize=DEFAULT_TREE_SIZE;nodes=new Node[treeSize];nodes[0]=new Node<E>(data,-1);nodeNums++;}//以指定根节点、指定treeSize创建树@SuppressWarnings("unchecked")public TreeParent(E data,int treeSize){this.treeSize=treeSize;nodes=new Node[treeSize];nodes[0]=new Node<E>(data,-1);nodeNums++;}//为指定节点添加子节点@SuppressWarnings("rawtypes")public void addNode(E data,Node parent){for(int i=0;i<treeSize;i++){if(nodes[i]==null){nodes[i]=new Node<E>(data,pos(parent));nodeNums++;return;}}throw new RuntimeException("该树已满，无法添加新节点！");}//判断树是否为空public boolean empty(){//根节点是否为空return nodes[0]==null;}//返回根节点public Node<E> root(){return nodes[0];}//返回指定节点（非根节点）的父节点@SuppressWarnings("rawtypes")public Node<E> parent(Node node){//每个节点的parent记录了其父节点的位置return nodes[node.parent];}//返回指定结点（非叶子节点的所有子节点）@SuppressWarnings("rawtypes")public List<Node<E>> children(Node parent){List<Node<E>> list=new ArrayList<Node<E>>();for(int i=0;i<treeSize;i++){//如果当前节点的父节点的位置等于parent节点的位置if(nodes[i]!=null&&nodes[i].parent==pos(parent)){list.add(nodes[i]);}}return list;}//返回该树的深度public int deep(){//记录节点的最大深度int max=0;for(int i=0;i<treeSize&&nodes[i]!=null;i++){//初始化本节点的深度int def=1;//m记录当前节点的父节点的位置int m=nodes[i].parent;//如果其父节点存在while(m!=-1&&nodes[m]!=null){//向上继续搜索父节点m=nodes[m].parent;def++;}if(max<def){max=def;}}//返回最大深度return max;}//返回包含指定值的节点@SuppressWarnings("rawtypes")public int pos(Node node){for(int i=0;i<treeSize;i++){//找到指定节点if(nodes[i]==node){return i;}}return -1;}}public class TreeParentTest {@SuppressWarnings("rawtypes")public static void main(String[] args) {TreeParent<String> tp=new TreeParent<String>("root");TreeParent.Node root=tp.root();System.out.println(root);tp.addNode("节点1",root);System.out.println("此树的深度："+tp.deep());tp.addNode("节点2",root);List<TreeParent.Node<String>> nodes=tp.children(root);System.out.println("根节点的第一个子节点："+nodes.get(0));tp.addNode("节点3", nodes.get(0));System.out.println("此树的深度："+tp.deep());}}

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