以二叉链表为二叉树的存储结构，设计一个算法判断一棵二叉树是否是正则二叉树。正则二叉树是指在二叉树中不存在度为1的结点。

以下是判断一棵二叉树是否是正则二叉树的Python算法：

# 定义二叉树节点类
class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

# 判断一棵二叉树是否是正则二叉树
def is_regular_binary_tree(root):
    if not root:
        return True
    if not root.left and not root.right:
        return True
    if not root.left or not root.right:
        return False
    return is_regular_binary_tree(root.left) and is_regular_binary_tree(root.right)

# 测试代码
# 创建一棵正则二叉树
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
root.right.left = TreeNode(6)
root.right.right = TreeNode(7)
print(is_regular_binary_tree(root)) # 输出：True

# 创建一棵非正则二叉树
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
root.right.left = TreeNode(6)
print(is_regular_binary_tree(root)) # 输出：False