ツリーの作成と遍歴
6325 ワード
package test;
import java.util.ArrayDeque;
import java.util.LinkedList;
import java.util.List;
/**
* : , 3
*
* 0: (C )
*
* 1:http://zhidao.baidu.com/question/81938912.html
*
* 2:http://cslibrary.stanford.edu/110/BinaryTrees.html#java
*
* @author [email protected] @date: 2011-5-17
*
*/
public class BinTreeTraverse2 {
private int[] array = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
private static List<Node> nodeList = null;
/**
* :
*
* @author [email protected] @date: 2011-5-17
*
*/
private static class Node {
Node leftChild;
Node rightChild;
int data;
Node(int newData) {
leftChild = null;
rightChild = null;
data = newData;
}
}
public void createBinTree() {
nodeList = new LinkedList<Node>();
// Node
for (int nodeIndex = 0; nodeIndex < array.length; nodeIndex++) {
Node node = new Node(array[nodeIndex]);
nodeList.add(node);
}
// lastParentIndex-1
for (int parentIndex = 0; parentIndex < array.length / 2 - 1; parentIndex++) {
//
nodeList.get(parentIndex).leftChild = nodeList.get(parentIndex * 2 + 1);
//
nodeList.get(parentIndex).rightChild = nodeList.get(parentIndex * 2 + 2);
}
// : ,
int lastParentIndex = array.length / 2 - 1;
//
nodeList.get(lastParentIndex).leftChild = nodeList.get(lastParentIndex * 2 + 1);
// ,
if (array.length % 2 == 1) {
nodeList.get(lastParentIndex).rightChild = nodeList.get(lastParentIndex * 2 + 2);
}
}
/**
*
*
* ,
*
* @param node
*
*/
public static void preOrderTraverse(Node node) {
if (node == null)
return;
System.out.print(node.data + " ");
preOrderTraverse(node.leftChild);
preOrderTraverse(node.rightChild);
}
/**
*
*
* ,
*
* @param node
*
*/
public static void inOrderTraverse(Node node) {
if (node == null)
return;
inOrderTraverse(node.leftChild);
System.out.print(node.data + " ");
inOrderTraverse(node.rightChild);
}
/**
*
*
* ,
*
* @param node
*
*/
public static void postOrderTraverse(Node node) {
if (node == null)
return;
postOrderTraverse(node.leftChild);
postOrderTraverse(node.rightChild);
System.out.print(node.data + " ");
}
public static void depthOrderTraversal(Node root){
if(root==null){
System.out.println("empty tree");
return;
}
ArrayDeque<Node> stack=new ArrayDeque<Node>();
// deque 。
stack.push(root);
while(stack.isEmpty()==false){
// deque 。
Node node=stack.pop();
System.out.print(node.data+" ");
if(node.rightChild!=null){
stack.push(node.rightChild);
}
if(node.leftChild!=null){
stack.push(node.leftChild);
}
}
System.out.print("
");
}
/**
*
*
* :
*/
public static void levelOrderTraversal(Node root){
if(root==null){
System.out.println("empty tree");
return;
}
ArrayDeque<Node> queue=new ArrayDeque<Node>();
queue.add(root);
while(queue.isEmpty()==false){
// deque 。
Node node=queue.remove();
System.out.print(node.data+" ");
if(node.leftChild!=null){
queue.add(node.leftChild);
}
if(node.rightChild!=null){
queue.add(node.rightChild);
}
}
System.out.print("
");
}
public static void main(String[] args) {
BinTreeTraverse2 binTree = new BinTreeTraverse2();
binTree.createBinTree();
// nodeList 0
Node root = nodeList.get(0);
System.out.println(" :");
preOrderTraverse(root);
System.out.println();
System.out.println(" :");
inOrderTraverse(root);
System.out.println();
System.out.println(" :");
postOrderTraverse(root);
System.out.println(" :");
depthOrderTraversal(root);
System.out.println(" :");
levelOrderTraversal(root);
}
}