HackMD
226.Invert Binary Tree
tags: Easy,Tree,BFS,DFS,Binary Tree
題目描述
Given the root of a binary tree, invert the tree, and return its root.
範例
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
解答
Python
class Solution:
def invertTree(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
if not root: return
root.left, root.right = self.invertTree(root.right), self.invertTree(root.left)
return root
Ron ChenSat, Feb 18, 2023
Javascript
function invertTree(root) {
if (root === null) return null;
const queue = [root];
while (queue.length) {
const node = queue.shift();
const temp = node.left;
node.left = node.right;
node.right = temp;
if (node.left) queue.push(node.left);
if (node.right) queue.push(node.right);
}
return root;
}
MarsgoatFeb 20, 2023
