Longest Consecutive Sequence (Hash Set)
Computes length of longest consecutive sequence in O(n) time using set lookup on streak origins.
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Asked in interviews at
Reference implementation (Python)
def longest_consecutive(nums):
num_set = set(nums)
longest = 0
for num in num_set:
if num - 1 not in num_set:
curr = num
streak = 1
while curr + 1 in num_set:
curr += 1
streak += 1
longest = max(longest, streak)
return longestEmbed this visualization
Drop a live, looping Longest Consecutive Sequence (Hash Set) canvas into a blog post or course page.
<iframe src="/embed/longest-consecutive" 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 (Hash Set)?
Longest Consecutive Sequence (Hash Set) runs in O(n) time and O(n) auxiliary space.
Is the Longest Consecutive Sequence (Hash Set) 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 (Hash Set) in interviews?
Longest Consecutive Sequence (Hash Set) shows up in interviews at Google, Amazon, Spotify.
How does the 3D visualization of Longest Consecutive Sequence (Hash Set) 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.