题解 | #树的子结构#
树的子结构
http://www.nowcoder.com/practice/6e196c44c7004d15b1610b9afca8bd88
采用递归思想: 首先判断两个树是否为空,若都为空则返回True; 若子树为空则返回True; 若父树为空,则返回False; 接下来判断根节点,若根节点不同则返回True; 然后依次判断其左子树和右子树。
# 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 pRoot1 TreeNode类
# @param pRoot2 TreeNode类
# @return bool布尔型
#
class Solution:
def is_True(self,node1,node2):
if not node1 and not node2:
return True
if not node1 and node2:
return False
if node1 and not node2:
return True
if(node1.val != node2.val):
return False
return self.is_True(node1.left, node2.left) and self.is_True(node1.right, node2.right)
def HasSubtree(self , pRoot1: TreeNode, pRoot2: TreeNode) -> bool:
# write code here
if not pRoot1 or not pRoot2:
return False
if self.is_True(pRoot1, pRoot2):
return True
return self.HasSubtree(pRoot1.left, pRoot2) or self.HasSubtree(pRoot1.right, pRoot2)js
