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22. Find Length of Cycle

After collision in Floyd's algorithm, keep fast fixed and count steps as slow circles the loop.

Time O(n) Space O(1)

Live loop — open the studio to scrub, add your own array, or race it in Battle Arena.

Asked in interviews at

Goldman SachsAdobeSalesforce

Reference implementation (Python)

def find_cycle_length(head):
    slow = fast = head
    while fast and fast.next:
        slow, fast = slow.next, fast.next.next
        if slow == fast:
            count = 1
            curr = slow.next
            while curr != slow:
                count += 1
                curr = curr.next
            return count
    return 0

Embed this visualization

Drop a live, looping 22. Find Length of Cycle canvas into a blog post or course page.

<iframe src="/embed/cycle-length" 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 22. Find Length of Cycle?

22. Find Length of Cycle runs in O(n) time and O(1) auxiliary space.

Is the 22. Find Length of Cycle 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 22. Find Length of Cycle in interviews?

22. Find Length of Cycle shows up in interviews at Goldman Sachs, Adobe, Salesforce.

How does the 3D visualization of 22. Find Length of Cycle 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.