翻转二叉树

翻转一棵二叉树

您在真实的面试中是否遇到过这个题？ 

Yes

样例

  1         1 / \       / \2   3  => 3   2   /       \  4         4

/** * Definition of TreeNode: * public class TreeNode { *     public int val; *     public TreeNode left, right; *     public TreeNode(int val) { *         this.val = val; *         this.left = this.right = null; *     } * } */public class Solution {    /**     * @param root: a TreeNode, the root of the binary tree     * @return: nothing     */    public void invertBinaryTree(TreeNode root) {         if(root==null)          return;          TreeNode temp=root.left;           root.left=root.right;           root.right=temp;           invertBinaryTree(root.left);           invertBinaryTree(root.right);               }}