剑指offer——树的子结构

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def isSubtree(self,pRoot1,pRoot2):
        if pRoot2==None:
            return True
        elif pRoot1==None or pRoot1.val!=pRoot2.val:
            return False
        return self.isSubtree(pRoot1.left,pRoot2.left) and self.isSubtree(pRoot1.right,pRoot2.right)
    def HasSubtree(self, pRoot1, pRoot2):
        # write code here
        if pRoot2==None or pRoot1==None:
            return False
        else:
            return self.isSubtree(pRoot1,pRoot2) or self.HasSubtree(pRoot1.left, pRoot2) or self.HasSubtree( pRoot1.right, pRoot2)