java实现操作给定的二叉树，将其变换为源二叉树的镜像。

二叉树的镜像定义：源二叉树

8
/  \
6   10
/ \  / \
5  7 9 11
镜像二叉树
8
/  \
10   6
/ \  / \

11 9 7 5
/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;

public TreeNode(int val) {
this.val = val;

}

}
*/
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
public class Solution
{
public void Mirror(TreeNode root)
{
if (root == null)
return;
if (root.left == null && root.right == null)
return;
// 先序遍历每个结点，如果有子结点就交换
TreeNode temp = null;
temp = root.left;
root.left = root.right;
root.right = temp;
// 递归
if (root.left != null)
Mirror(root.left);
if (root.right != null)
Mirror(root.right);
}

// 从上到下打印一棵树
public ArrayList<Integer> PrintFromTopToBottom(TreeNode root)
{
ArrayList<Integer> list = new ArrayList<Integer>();
if (root == null)
{
return list;
}
Queue<TreeNode> queue = new LinkedList<TreeNode>();
queue.add(root);
while (!queue.isEmpty())
{
TreeNode treeNode = queue.poll();
list.add(treeNode.val);
if (treeNode.left != null)
{
queue.add(treeNode.left);
}
if (treeNode.right != null)
{
queue.add(treeNode.right);
}
}
return list;
}

public static void main(String[] args)
{
TreeNode root = new TreeNode(8);
root.left = new TreeNode(6);
root.right = new TreeNode(10);
root.left.left = new TreeNode(5);
root.left.right = new TreeNode(7);
root.right.left = new TreeNode(9);
root.right.right = new TreeNode(11);
Solution s = new Solution();
ArrayList<Integer> list = s.PrintFromTopToBottom(root);
for (int i = 0; i < list.size(); i++)
{
System.out.print(list.get(i) + ",");
}

s.Mirror(root);
System.out.println("");
System.out.print("镜像为:");
ArrayList<Integer> list1 = s.PrintFromTopToBottom(root);
for (int i = 0; i < list1.size(); i++)
{
System.out.print(list1.get(i) + ",");
}
}

}