Previous Greater Element
Finds nearest larger element to the left using monotonic stack.
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_greater(arr):
res = [-1] * len(arr)
stack = []
for i in range(len(arr)):
while stack and stack[-1] <= arr[i]: stack.pop()
if stack: res[i] = stack[-1]
stack.append(arr[i])
return resEmbed this visualization
Drop a live, looping Previous Greater Element canvas into a blog post or course page.
<iframe src="/embed/previous-greater-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 Greater Element?
Previous Greater Element runs in O(n) time and O(n) auxiliary space.
Is the Previous Greater 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 Greater Element in interviews?
Previous Greater Element shows up in interviews at Spotify, Google, Airbnb.
How does the 3D visualization of Previous Greater 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.