cpp-flashcards/org/study_deck_02/dsa/trees/0226-invert-binary-tree.org

#+ANKI_DECK: study_deck_02
* TODO 0226. Invert Binary Tree :easy:
:PROPERTIES:
:NEETCODE: [[file:../../roadmap.org::*0226. Invert Binary Tree][0226. Invert Binary Tree]]
:END:

Given the ~root~ of a binary tree, invert the tree, and return /its root/.

*Example 1:*


#+begin_src
Input: root = [4,2,7,1,3,6,9]
Output: [4,7,2,9,6,3,1]
#+end_src


*Example 2:*


#+begin_src
Input: root = [2,1,3]
Output: [2,3,1]
#+end_src


*Example 3:*


#+begin_src
Input: root = []
Output: []
#+end_src


*Constraints:*

 - The number of nodes in the tree is in the range ~[0, 100]~.

 - ~-100 <= Node.val <= 100~

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python :lc-problem 226 :lc-lang python3
# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
#+end_src

** TODO C++
#+begin_src cpp :lc-problem 226
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    TreeNode* invertTree(TreeNode* root) {
        
    }
};
#+end_src