image.png
image.png
第一步，需要在树A中找到与树B根节点一样的节点
第二步，从找到的这个节点出发，比较树B是否是树A的子结构：分别遍历，当树B空的时候,是子树，如果两个值不符，不是子树
代码：
# -*- coding:utf-8 -*-
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def HasSubtree(self, pRoot1, pRoot2):
# write code here
result = False
if pRoot1 != None and pRoot2 != None:
if pRoot1.val == pRoot2.val:
result = self.DoesTree1HaveTree2(pRoot1, pRoot2)
if not result:
result = self.HasSubtree(pRoot1.left, pRoot2)
if not result:
result = self.HasSubtree(pRoot1.right, pRoot2)
return result
def DoesTree1HaveTree2(self,pRoot1, pRoot2):
if pRoot2 == None:
return True
if pRoot1 == None:
return False
if pRoot1.val != pRoot2.val:
return False
return self.DoesTree1HaveTree2(pRoot1.left, pRoot2.left) and self.DoesTree1HaveTree2(pRoot1.right, pRoot2.right)
