java資料結構—-二叉樹

1.   實現二叉樹的各種遍曆

package com.jzm.stackQueueTree;public class BinTree {  private final static int MAX = 50;  private Object  data;  private BinTree left,right;    BinTree[] elements = new BinTree[MAX];  int front ;  int rear;       public BinTree() {    }    public BinTree(Object data) {   this.data = data;   left = right = null;  }     public BinTree(Object data,BinTree left,BinTree right){  this.data = data;  this.left = left;  this.right = right;      }      @Overridepublic String toString() {         return data.toString();}                    //前序走訪        public static void preOrder(BinTree parent){     if (parent == null) { return; }           System.out.print(parent.data+" ");    preOrder(parent.left);    preOrder(parent.right);       }          //中序遍曆    public static void inOrder(BinTree parent){     if (parent == null) { return; }           inOrder(parent.left);    System.out.print(parent.data+" ");    inOrder(parent.right);       }          //後序遍曆    public static void postOrder(BinTree parent){     if (parent == null) { return; }           postOrder(parent.left);    postOrder(parent.right);       System.out.print(parent.data+" ");    }      //層次遍曆        public void LayerOrder(BinTree parent){       elements[0] = parent;    front = 0;    rear = 1;    while(front < rear){    try{        if (elements[front].data != null) {    System.out.print(elements[front].data+" ");     if(elements[front].left !=null)          elements[rear++] = elements[front].left;                          if(elements[front].right !=null)          elements[rear++] = elements[front].right;              front++;          }//end if      }catch(Exception e){break;    }          } //end while      }          //求樹的高度    public  int  height(){      int height = 0;      if(this ==null){      return -1;      }           int  leftHeigt = ( (left == null)? 0:left.height() );      int  rightHeigt=( (right ==null)?0:right.height() );      height = leftHeigt < rightHeigt ?rightHeigt:leftHeigt;          return height+1;    }     //如果對象不在樹中，結果返回-1，否則返回對象在樹中的層次，規定根節點為第一層       public   int  level(Object object){            int  levelTree =0;        if(this == null){    return -1;    }      //規定根節點為第一層    if(object.equals(data)){          return  1;       }      int  leftLevel  = (  (left == null)?  -1:left.level(object) );    int  rightLevel = (  (right ==null)?  -1:right.level(object) );       if (leftLevel < 0 &&  rightLevel < 0) {      return -1;  }       levelTree = (leftLevel < rightLevel)? rightLevel:leftLevel;             return   levelTree+1;  }       //將樹中每一個節點的孩子對換位置     public void reflect(){         if(this == null)    return ;    if (left != null) {left.reflect();}    if(right != null){    right.reflect();    }    BinTree temp = left;    left = right;    right = temp;         }        //將樹中所有的節點移走，並輸出移走的節點        public  void   defoliate(){    String innerNode = "";    if(this == null)    return;    //如為分葉節點，移走    if(left == null && right ==null){     System.out.print(this + "");     data = null;     return ;       }        //移走左子樹    if(left != null){    left.defoliate();    left = null;    }        innerNode += this +" ";    data = null;        //移走右子樹    if(right != null){    right.defoliate();    right = null;    }         }        public static void main(String[] args) {     BinTree e = new BinTree("E");     BinTree g = new BinTree("G");            BinTree h = new BinTree("H");            BinTree i = new BinTree("I");             BinTree d = new BinTree("D",null,g);          BinTree f = new BinTree("F",h,i);        BinTree b = new BinTree("B",d,e);     BinTree c = new BinTree("C",f,null);            BinTree tree = new BinTree("A", b, c);              System.out.println("heigh="+tree.height());              System.out.println("前序結果：");     tree.preOrder(tree);         System.out.println("");          System.out.println("中序結果：");     tree.inOrder(tree);         System.out.println("");             System.out.println("後序結果：");     tree.postOrder(tree);         System.out.println("");          System.out.println("層次遍曆結果：");     tree.LayerOrder(tree);         System.out.println("");          System.out.println("level(d)"+tree.level("B"));   }      }