Invert a binary tree.
4 / 2 7 / \ / 1 3 6 9
to
4 / 7 2 / \ / 9 6 3 1
Trivia:
This problem was inspired by this original tweet by Max Howell:
解题思路：
递归即可，JAVA实现如下：
public TreeNode invertTree(TreeNode root) {
if(root==null)
return root;
TreeNode temp=root.left;
root.left=root.right;
root.right=temp;
invertTree(root.left);
invertTree(root.right);
return root;
}
Java for LeetCode 226 Invert Binary Tree
原文：http://www.cnblogs.com/tonyluis/p/4579100.html