题解 | #重建二叉树#

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
#
# @param pre int整型一维数组
# @param vin int整型一维数组
# @return TreeNode类
#
class Solution:
    def reConstructBinaryTree(self, pre: list[int], vin: list[int]) -> TreeNode:
        # write code here
        if not pre:
            return None
        node = TreeNode(pre[0])
        index = vin.index(pre[0])

        node.left = self.reConstructBinaryTree(pre[1 : index + 1], vin[:index])
        node.right = self.reConstructBinaryTree(pre[index + 1 :], vin[index + 1 :])
        return node