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18. Merge Two Sorted Linked Lists ⭐

Splices two sorted lists into one ordered list by picking the smaller head at each comparison.

Time O(n + m) Space O(1)

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

Asked in interviews at

AtlassianShopifyLinkedIn

Reference implementation (Python)

def merge_two_lists(l1, l2):
    dummy = ListNode(0)
    tail = dummy
    while l1 and l2:
        if l1.val <= l2.val:
            tail.next = l1
            l1 = l1.next
        else:
            tail.next = l2
            l2 = l2.next
        tail = tail.next
    tail.next = l1 or l2
    return dummy.next

Embed this visualization

Drop a live, looping 18. Merge Two Sorted Linked Lists ⭐ canvas into a blog post or course page.

<iframe src="/embed/merge-two-sorted-lists" 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 18. Merge Two Sorted Linked Lists ⭐?

18. Merge Two Sorted Linked Lists ⭐ runs in O(n + m) time and O(1) auxiliary space.

Is the 18. Merge Two Sorted Linked Lists ⭐ 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 18. Merge Two Sorted Linked Lists ⭐ in interviews?

18. Merge Two Sorted Linked Lists ⭐ shows up in interviews at Atlassian, Shopify, LinkedIn.

How does the 3D visualization of 18. Merge Two Sorted Linked Lists ⭐ 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.