103. Binary Tree Zigzag Level Order Traversal

# 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 zigzagLevelOrder(self, root):
        """
        :type root: TreeNode
        :rtype: List[List[int]]
        """
        queueLeft = [root]
        queueRight = []
        temp = []
        result = []
        
        if not root:
            return []
        
        if root == []:
            return []
        
        while queueLeft or queueRight:
            while queueLeft != []:
                if queueLeft[0].left:
                    queueRight.append(queueLeft[0].left) 
                if queueLeft[0].right:
                    queueRight.append(queueLeft[0].right) 
                temp.append(queueLeft.pop(0).val)
                
            if temp != []:
                result.append(temp)
                temp = []
            
            while queueRight != []:
                if queueRight[0].left:
                    queueLeft.append(queueRight[0].left)
                if queueRight[0].right:
                    queueLeft.append(queueRight[0].right) 
                temp.append(queueRight.pop(0).val)
            
            if temp != []:
                temp.reverse()
                result.append(temp)
                temp = []
        
        return result