代码语言：javascript复制
/**
* Definition for a binary tree node.
* function TreeNode(val) {
* this.val = val;
* this.left = this.right = null;
* }
*/
/**
* @param {TreeNode} root
* @return {TreeNode}
*/
var invertTree = function(root) {
if(root == null) return null;
var tmpNode = root.left;
root.left = invertTree(root.right);
root.right = invertTree(tmpNode);
return root;
};
