[Leetcode][python]Symmetric Tree/对称二叉树

class Solution(object):
    def judge(self, p, q):
        if p == None and q == None: 
            return True
        if p and q and p.val == q.val: # 如果一边有一边没有那么直接返回False
            return self.judge(p.left, q.right) and self.judge(p.right, q.left)
        return False

    def isSymmetric(self, root):
        """
        :type root: TreeNode
        :rtype: bool
        """
        if root:
            return self.judge(root.left, root.right)
        return True

class Solution(object):
    def isSymmetric(self, root):
        """
        :type root: TreeNode
        :rtype: bool
        """
        def isSym(L,R):
            if L and R and L.val == R.val: 
                return isSym(L.left, R.right) and isSym(L.right, R.left)
            return L == R
        return isSym(root, root)

class Solution(object):
    def isSymmetric(self, root):
        queue = [root]
        while queue:
            values = [i.val if i else None for i in queue]
            if values != values[::-1]: return False
            queue = [child for i in queue if i for child in (i.left, i.right)]
        return True