00226_invert_binary_tree

Invert Binary Tree

Link to Problem: https://leetcode.com/problems/invert-binary-tree

Description

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

Examples

Example 1

graph
  A((4)) --> B((2))
  A --> C((7))
  B --> D((1))
  B --> E((3))
  C --> F((6))
  C --> G((9))

  H((4)) --> I((7))
  H --> J((2))
  I --> K((9))
  I --> L((6))
  J --> M((3))
  J --> N((1))

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Input: root = [4,2,7,1,3,6,9]
Output: [4,7,2,9,6,3,1]

Example 2

graph
  A((2)) --> B((1))
  A --> C((3))

  D((2)) --> E((3))
  D --> F((1))

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Input: root = [2,1,3]
Output: [2,3,1]

Example 3

Input: root = []
Output: []

Thoughts

Elixir just continues to be a really good language to use because of how simple the code turned out to be.

Apparently, the algorithm is called DFS or Depth-first Search according to NeetCode, but looking at the way the example was drawn made it obvious about how to handle the inversion.