Previous Smaller Element
Finds nearest element to left strictly smaller than current element.
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 prev_smaller(arr):
res = [-1] * len(arr)
for i in range(len(arr)):
for j in range(i - 1, -1, -1):
if arr[j] < arr[i]:
res[i] = arr[j]; break
return resEmbed this visualization
Drop a live, looping Previous Smaller Element canvas into a blog post or course page.
<iframe src="/embed/previous-smaller-element" 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 Previous Smaller Element?
Previous Smaller Element runs in O(n) time and O(n) auxiliary space.
Is the Previous Smaller Element 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 Previous Smaller Element in interviews?
Previous Smaller Element shows up in interviews at Microsoft, Apple, Bloomberg.
How does the 3D visualization of Previous Smaller Element 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.