94. Binary Tree Inorder Traversal

📋 Đề Bài

Given the root of a binary tree, return the inorder traversal of its nodes' values.

Example 1:

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

Example 2:

Input: root = []
Output: []

Example 3:

Input: root = [1]
Output: [1]

Constraints:

The number of nodes in the tree is in the range [0, 100].
-100 <= Node.val <= 100

Follow up: Recursive solution is trivial, could you do it iteratively?

🧠 Thuật Toán & Kỹ Thuật

Tree Traversal (Duyệt cây)

⏱️ Thời gian O(n)

💾 Không gian O(n)

💻 Lời Giải

Python 0094-binary-tree-inorder-traversal.py

# 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 inOrder(self, root):
        if root:
            self.inOrder(root.left)
            self.ans.append(root.val)
            self.inOrder(root.right)
            
    def inorderTraversal(self, root: Optional[TreeNode]) -> List[int]:
        self.ans = []
        self.inOrder(root)
        return self.ans