python重建二叉树

Posted 2021-02-08

 

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
 
def contree(pre,tin):
    if len(tin)==1 and len(pre)==1:
        return TreeNode(tin[0])
    if pre==[] and tin==[]:
        return None
     
    for i in range(0,len(tin)):
        if tin[i]==pre[0]:
            print pre[1:1+i]
            print pre[1+i:]
            lt=contree(pre[1:1+i],tin[:i])
            rt=contree(pre[i+1:],tin[i+1:])
            tempnode=TreeNode(tin[i])
            tempnode.left=lt
            tempnode.right=rt
            return tempnode
 
class Solution:
    # 返回构造的TreeNode根节点
    def reConstructBinaryTree(self, pre, tin):
        # write code here
        return contree(pre,tin)