数据类型之二叉树小结

之前学习了数据类型中的链表，在数据类型中还有一种树形结构，而二叉树即是一种数。二叉树跟双向链表有些相似，二叉树也有父结点和子结点，只是子结点有两个，一个是左结点，一个是右结点。

public class TreeNode<E> {
	//左结点、右结点、父结点
	private TreeNode<E> left;
	private TreeNode<E> right;
	private TreeNode<E> parent;
	private E data;
	//结点的构造器，存储入数据
	public TreeNode(E e){
		this.setData(e);
	}
	//设置父结点的方法
	public void setParent(TreeNode<E> parent) {
		this.parent = parent;
	}
	//得到父结点的方法
	public TreeNode<E> getParent() {
		return parent;
	}
	//设置左结点的方法
	public void setLeft(TreeNode<E> left) {
		this.left = left;
	}
	//得到左结点的方法
	public TreeNode<E> getLeft() {
		return left;
	}
	//设置右结点的方法
	public void setRight(TreeNode<E> right) {
		this.right = right;
	}
	//得到右结点的方法
	public TreeNode<E> getRight() {
		return right;
	}
	//存储入数据的方法
	public void setData(E data) {
		this.data = data;
	}
	//得到数据的方法
	public E getData() {
		return data;
	}
}

下面我们测试一下二叉树：

public class TreeNodeTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		paintTree(CreatTree());
	}
	/**
	 * 建树
	 * @return：树的根节点
	 */
	public static TreeNode<String> CreatTree(){
		TreeNode<String> root = new TreeNode<String>("媒");
		root.setParent(root);
		TreeNode<String> left = new TreeNode<String>("杰");
		TreeNode<String> right = new TreeNode<String>("李");
		
		root.setLeft(left);
		root.setRight(right);
		left.setParent(root);
		right.setParent(root);
		
		TreeNode<String> left_left = new TreeNode<String>("蓝");
		TreeNode<String> left_right = new TreeNode<String>("数");
		
		left.setLeft(left_left);
		left.setRight(left_right);
		left_left.setParent(left);
		left_right.setParent(left);
		
		TreeNode<String> right_left = new TreeNode<String>("班");
		TreeNode<String> right_right = new TreeNode<String>("勇");
		
		right.setLeft(right_left);
		right.setRight(right_right);
		right_left.setParent(right);
		right_right.setParent(right);
		
		return root;
	}
	/**
	 * 打印数中的数据
	 * @param root:树的根节点
	 */
	public static void paintTree(TreeNode<String> root){
		if(root!=null){
		String s = root.getData();
		System.out.println("数据是:"+s);
		TreeNode<String> node1 = root.getLeft();
		TreeNode<String> node2 = root.getRight();
		paintTree(node1);
		paintTree(node2);
		}
	}
}

这样一个简单的二叉树就完成了。