226. Invert Binary Tree

원문: https://doljae.tistory.com/108

[Invert Binary Tree - LeetCode

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leetcode.com](https://leetcode.com/problems/invert-binary-tree/)

1. Queue를 이용한 풀이

from collections import deque

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        if not root:
            return None
        if not root.left and not root.right:
            return root
        q = deque([])
        q.append(root)
        while q:
            print(q)
            cur = q.popleft()
            if not cur:
                continue
            q.append(cur.left)
            q.append(cur.right)
            cur.left, cur.right = cur.right, cur.left
        return root

2. 재귀를 이용한 풀이

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        if not root:
            return None
        root.left = self.invertTree(root.left)
        root.right = self.invertTree(root.right)
        root.left, root.right = root.right, root.left
        return root



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