Longest Subarray with at most K Distinct
Two-pointer sliding window expands and contracts to maintain at most K unique keys.
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_k_distinct(arr, k=2):
count = {}; left = max_len = 0
for right, x in enumerate(arr):
count[x] = count.get(x, 0) + 1
while len(count) > k:
count[arr[left]] -= 1
if count[arr[left]] == 0: del count[arr[left]]
left += 1
max_len = max(max_len, right - left + 1)
return max_lenEmbed this visualization
Drop a live, looping Longest Subarray with at most K Distinct canvas into a blog post or course page.
<iframe src="/embed/longest-subarray-k-distinct" 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 Subarray with at most K Distinct?
Longest Subarray with at most K Distinct runs in O(n) time and O(k) auxiliary space.
Is the Longest Subarray with at most K Distinct 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 Subarray with at most K Distinct in interviews?
Longest Subarray with at most K Distinct shows up in interviews at Amazon, Apple, Stripe.
How does the 3D visualization of Longest Subarray with at most K Distinct 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.