Problem

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:

!https://assets.leetcode.com/uploads/2020/12/20/ex1.jpg

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

Example 2:

!https://assets.leetcode.com/uploads/2020/12/20/ex2.jpg

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

Example 3:

!https://assets.leetcode.com/uploads/2020/12/20/ex3.jpg

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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].
  • 10^4 <= Node.val <= 10^4

Solve

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class Solution:
    def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
        if not p and not q:
            return True
        elif not p or not q or p.val != q.val:
            return False
        return (self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right))