思路
遞歸三要素
1、遞歸出口:最簡(jiǎn)單的情況辨液,樹高為1
2虐急、分解子問題:求左子樹、右子樹情況
3滔迈、父問題與子問題的交集
代碼
class Solution:
def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
if p is None and q is None:
return True
if p is None or q is None:
return False
if p.val != q.val:
return False
return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)
復(fù)雜度
時(shí)間復(fù)雜度:o(n)止吁,n為節(jié)點(diǎn)個(gè)數(shù)
空間復(fù)雜度:o(h),h為樹高度