算法中常用的树操作
树的数据结构
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
1、树的子结构
输入两棵二叉树A,B,判断B是不是A的子结构。(ps:我们约定空树不是任意一个树的子结构)
class Solution:
def HasSubtree(self, pRoot1, pRoot2):
# write code here
if pRoot2==None or pRoot1==None:
return False
return self.isSubtree(pRoot1,pRoot2) or self.HasSubtree(pRoot1.left,pRoot2) or self.HasSubtree(pRoot1.right,pRoot2)
def isSubtree(self, pRoot1, pRoot2):
if pRoot2==None:
return True
elif pRoot1==None and pRoot2!=None:
return False
else:
return pRoot1.val==pRoot2.val and self.isSubtree(pRoot1.left,pRoot2.left) and self.isSubtree(pRoot1.right,pRoot2.right)
2、二叉树的深度
class Solution:
def TreeDepth(self,pRoot):
if pRoot==None:
return 0
return max(self.TreeDepth(pRoot.left)+1,self.TreeDepth(pRoot.right)+1)