100. Same Tree

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
        """
        def same(a,b):
            f=False
            if a==None and b==None:
                return True
            else:
                if a==None or b==None:
                    return False
                else:
                    if a.val==b.val:
                        f=True
                    return f and same(a.left,b.left) and same(a.right,b.right)
        return same(p,q)