SameTree.py

"""
Given two binary trees, write a function to check if they are equal or not.
Two binary trees are considered equal if they are structurally identical and the nodes have the same value.
"""


# Definition for a binary tree node.
class TreeNode(object):
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None


class Solution(object):
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        if p is None and q is None:
            return True
        elif (p is None and q is not None) or (p is not None and q is None):
            return False
        else:
            if p.val != q.val:
                return False
            else:
                return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)