25. Zigzag / Spiral Level Order
Level order traversal alternating direction between left-to-right and right-to-left at each tier.
Live loop — open the studio to scrub, add your own array, or race it in Battle Arena.
Asked in interviews at
Reference implementation (Python)
def zigzag_level_order(root):
if not root: return []
res, queue, left_to_right = [], deque([root]), True
while queue:
level = deque()
for _ in range(len(queue)):
node = queue.popleft()
if left_to_right: level.append(node.val)
else: level.appendleft(node.val)
if node.left: queue.append(node.left)
if node.right: queue.append(node.right)
res.append(list(level))
left_to_right = not left_to_right
return resEmbed this visualization
Drop a live, looping 25. Zigzag / Spiral Level Order canvas into a blog post or course page.
<iframe src="/embed/tree-zigzag" width="100%" height="380" style="border:1px solid #e6e8ec;border-radius:14px" loading="lazy" title="3D algorithm visualization by CodeWithMunnaX"></iframe>Frequently asked
What is the time and space complexity of 25. Zigzag / Spiral Level Order?
25. Zigzag / Spiral Level Order runs in O(n) time and O(n) auxiliary space.
Is the 25. Zigzag / Spiral Level Order visualizer free?
The core 3D visualizer, Web Audio chimes and step intuition are free. A one-time ₹49 Pro Pass unlocks advanced algorithms, large custom arrays, Battle Arena and reel export.
Which companies ask 25. Zigzag / Spiral Level Order in interviews?
25. Zigzag / Spiral Level Order shows up in interviews at Amazon, Apple, Stripe.
How does the 3D visualization of 25. Zigzag / Spiral Level Order work?
Each array value becomes a 3D pillar whose height maps to its value. Comparisons glow amber, swaps flash red, and settled elements lock green while a floating pointer badge tracks the active index — synchronized line-by-line with the Python code.