Zig Zag or Spiral traversal in Binary Tree

Info

Intuition

Striver series notes

• The direction needs to be changed after every iteration.
• 

Attempt

'''
do level order traversal by using queue
use a flag and toggle it after every iteration
based on flag do popleft or popright 
if I popright then the next layer values will be stored in reverse order
 
puesdo code:
if root == none:
    return []
    
queue = deque()
layer = []
toggle = 0
while queue:
    toggle = !toggle
    for i in range(len(q)):
'''
 
class TreeNode(object):
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right
class Solution(object):
    def zigzagLevelOrder(self, root):
        """
        :type root: TreeNode
        :rtype: List[List[int]]
        """
        

Links

• https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/?envType=study-plan-v2&envId=top-interview-150