Same Tree
Intuition Check all items simultaneosly Approach Complexity Time complexity: O(n) Space complexity: O(1) Code # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, val=0, left=None, right=None): # self.val = val # self.left = left # self.right = right class Solution(object): def isSameTree(self, p, q): """ :type p: Optional[TreeNode] :type q: Optional[TreeNode] :rtype: bool """ if not p and not q: return True if not p or not q: return False if p.val != q.val: return False return self.isSameTree(p.right, q.right) and self.isSameTree(p.left, q.left)