[LeetCode] 144. Binary Tree Preorder Traversal 문제 풀이

이진 트리(Binary Tree)의 값을 전위 순회(Preorder Traversal)하면서 값을 반환하는 문제입니다.

 

LeetCode : https://leetcode.com/problems/binary-tree-preorder-traversal/

Binary Tree Preorder Traversal - LeetCode

 

Code(Python)

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution(object):
    def preorderTraversal(self, root):
        """
        :type root: TreeNode
        :rtype: List[int]
        """
        res = []

        def preorder(root):
            if root:
                res.append(root.val)
                preorder(root.left)
                preorder(root.right)

        preorder(root)

        return res