二叉树的镜像

// 二叉树的结构
class BinaryTreeNode{
	String data;
	BinaryTreeNode left;
	BinaryTreeNode right;
}
/**
 *  输入一个二叉树，输出它的镜像
 */
public class BitreeMirrorImg {
	Scanner scanner = new Scanner(System.in);
	//建立二叉树
	public BinaryTreeNode createTree(BinaryTreeNode root){
		String data;
		data = scanner.next();
		if(data.equals("#")){
			return null;
		}
		root = new BinaryTreeNode();
		root.data = data;
		root.left = createTree(root.left);
		root.right = createTree(root.right);
		return root;
	}
	//得到二叉树的镜像
	public void mirror(BinaryTreeNode root){
		if(root == null){
			return;
		}
		if((root.left == null) && (root.right == null)){
			return;
		}
		BinaryTreeNode temp = root.left;
		root.left = root.right;
		root.right = temp;
		mirror(root.left);
		mirror(root.right);
	}
	//层次遍历二叉树
	public void levelTraverse(BinaryTreeNode root){
		java.util.LinkedList





 list= new java.util.LinkedList();
		list.add(root);
		while(list.size() != 0){
			BinaryTreeNode node = list.removeFirst();
			System.out.print(node.data + " ");
			if(node.left != null){
				list.add(node.left);
			}
			if(node.right != null){
				list.add(node.right);
			}
		}
	}
	public static void main(String[] args) {
		BitreeMirrorImg bmi = new BitreeMirrorImg();
		BinaryTreeNode root = null;
		root = bmi.createTree(root);
		bmi.mirror(root);
		bmi.levelTraverse(root);
	}
}