Merge In Between Linked Lists
A medium-tier problem at 82% community acceptance, tagged with Linked List. Reported in interviews at Arista Networks and 2 others.
Merge In Between Linked Lists is a medium-difficulty linked list problem that shows up in assessments at Arista Networks, PayPal, and Oracle. The acceptance rate sits at 82%, which sounds high until you realize most candidates who fail do so because they miss the pointer-reconnection logic under pressure. You're given two lists and indices defining a range; your job is to splice one list into another at that range. It's not hard conceptually, but the actual pointer manipulation trips people up in a live OA. If you blank on the exact reconnection sequence, StealthCoder runs invisibly during your assessment and surfaces a working solution in seconds.
Companies that ask "Merge In Between Linked Lists"
Merge In Between Linked Lists is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Built by an engineer at a top-10 tech company who can solve these problems cold but didn't want to trust himself in a 90-minute screen share.
Get StealthCoderThe trap here is that you need to think in three moves: find the node before your range, find the tail of the list you're inserting, and then rewire four pointers to glue everything together. The obvious approach is to iterate to the indices, but candidates often reconnect in the wrong order or lose track of which node points where, especially when they're nervous. The twist is that you have to preserve the tail of the second list while orphaning the middle section of the first. Most candidates can write the basic traversal but fumble the pointer assignments. This is pure execution skill under time pressure. If you've drilled linked list problems before, your muscle memory usually carries you. If you haven't, or if the indices logic catches you mid-OA, StealthCoder is your safety net to keep the assessment moving.
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Merge In Between Linked Lists recycles across companies for a reason. It's medium-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Built by an engineer at a top-10 tech company who can solve these problems cold but didn't want to trust himself in a 90-minute screen share. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Merge In Between Linked Lists interview FAQ
Is this problem actually asked at FAANG?+
It appears in assessments at PayPal and Oracle, both major platforms. The 82% acceptance rate suggests it's a screening filter for candidates who can handle pointer manipulation cleanly. Not every candidate sees it, but enough do that it's worth drilling.
What's the actual trick I'm supposed to find?+
There's no clever algorithm. The trick is the pointer sequence: find the predecessor of your range start, find the tail of the list you're inserting, then execute four pointer assignments in the right order. One wrong reassignment breaks the whole structure.
How much harder is this than a basic linked list reversal?+
It's about the same difficulty. You need the same pointer traversal skill, but you're managing three separate pointer movements instead of one. If you've done 'Reverse a Linked List' cleanly, you can handle this with focus.
Will I have time to debug if I get the pointers wrong?+
Not in a typical OA time box. Pointer bugs in linked lists are silent until you print the result, and by then you've already burned 10-15 minutes. That's why getting the logic right the first time matters under pressure.
Do I need to handle edge cases like empty lists or out-of-bound indices?+
The problem statement usually guarantees valid inputs, but always read the constraints. Companies like PayPal and Oracle sometimes include boundary cases in their test suite. Assume you do and write defensively.
Want the actual problem statement? View "Merge In Between Linked Lists" on LeetCode →