LeetCode 100 Same Tree

LeetCode

Given the roots of two binary trees p and q, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.

Example 1:

Input: p = [1,2,3], q = [1,2,3]
Output: true

Example 2:

Input: p = [1,2], q = [1,null,2]
Output: false

Example 3:

Input: p = [1,2,1], q = [1,1,2]
Output: false

Constraints:

The number of nodes in both trees is in the range [0, 100]. -10<sup>4</sup> <= Node.val <= 10<sup>4</sup>

题目大意：

判断二叉树是否相等

解题思路：

类似于Leetcode 101 Symmetric Tree但稍简单, easy题

解题步骤：

N/A

注意事项：

1. Python代码：

   def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
   	if not p and not q:
   		return True
   	if not p or not q:
   		return False
   	return p.val == q.val and self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

算法分析：

时间复杂度为O(n)，空间复杂度O(1)