leetcode

Binary Tree Zigzag Level Order Traversal

Binary Tree Zigzag Level Order Traversal

Binary Search Version - 36ms

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# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def zigzagLevelOrder(self, root):
        """
        :type root: TreeNode
        :rtype: List[List[int]]
        """
        if not root:
            return []
        queue = [root]
        res = []
        level = 0
        while queue:
            level += 1
            temp = []
            tempq = []
            for node in queue:
                temp.append(node.val)
                if node.left:
                    tempq.append(node.left)
                if node.right:
                    tempq.append(node.right)
            queue = tempq
            if level % 2 == 0 :
                temp = temp[::-1]
            res.append(temp)
        return res

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