226. Invert Binary Tree
Given the root of a binary tree, invert the tree, and return its root.
Example 1
Input: root = [4,2,7,1,3,6,9]
Output: [4,7,2,9,6,3,1]
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
public TreeNode invertTree(TreeNode root) {
if(root==null){
return null;
}
TreeNode tmp=root.left;
root.left=root.right;
root.right=tmp;
invertTree(root.left);
invertTree(root.right);
return root;
}
}