LeetCode in Elixir
226. Invert Binary Tree
Easy
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]
Example 2:
Input: root = [2,1,3]
Output: [2,3,1]
Example 3:
Input: root = []
Output: []
Constraints:
- The number of nodes in the tree is in the range
[0, 100]. -100 <= Node.val <= 100
Solution
defmodule Solution do
@spec invert_tree(root :: TreeNode.t | nil) :: TreeNode.t | nil
def invert_tree(%TreeNode{val: v, left: left, right: right}) do
%TreeNode{val: v, left: invert_tree(right), right: invert_tree(left)}
end
def invert_tree(nil), do: nil
end