LeetCode, Invert Binary Tree (Java)

leetcode.com/problems/invert-binary-tree/

Invert Binary Tree - LeetCode

Invert a binary tree.

Input:

     4
   /   \
  2     7
 / \   / \
1   3 6   9
Output:

     4
   /   \
  7     2
 / \   / \
9   6 3   1

재귀를 이용해서 왼쪽과 오른쪽을 바꾸고 할당한다.

class Solution {
    public TreeNode invertTree(TreeNode root) {
        if(root == null){
            return null;
        }
        
        TreeNode right = invertTree(root.right);
        TreeNode left = invertTree(root.left);
        
        root.left = right;
        root.right = left;
        
        return root;
    }
}