Longest Consecutive Sequence
Builds O(1) lookup hash set to find consecutive chain without sorting.
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 longest_consecutive(arr):
s = set(arr)
longest = 0
for x in s:
if x - 1 not in s:
curr, count = x, 1
while curr + 1 in s:
curr += 1; count += 1
longest = max(longest, count)
return longestEmbed this visualization
Drop a live, looping Longest Consecutive Sequence canvas into a blog post or course page.
<iframe src="/embed/longest-consecutive-sequence" 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 Longest Consecutive Sequence?
Longest Consecutive Sequence runs in O(n) time and O(n) auxiliary space.
Is the Longest Consecutive Sequence 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 Longest Consecutive Sequence in interviews?
Longest Consecutive Sequence shows up in interviews at Amazon, Apple, Stripe.
How does the 3D visualization of Longest Consecutive Sequence 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.