Get Server Index
Reported by candidates from TikTok's online assessment. Pattern, common pitfall, and the honest play if you blank under the timer.
TikTok's "Get Server Index" problem hit assessments in February 2024, and it's a routing or indexing puzzle that catches candidates off guard. You've got a set of servers, some kind of query structure, and you need to figure out which server handles what. The pattern isn't always obvious at first read, which is exactly why StealthCoder exists: to help you map the problem's real constraint the moment you see it live, so you don't waste 15 minutes spinning on the wrong approach.
Pattern and pitfall
Without the full problem text, the title suggests either a hash-based modulo assignment (consistent hashing or simple indexing) or a binary search to locate server ranges. The trick is usually in how the servers are distributed or how the query key maps to them. Common pitfall: candidates assume a linear scan when the solution needs indexing math or a preprocessed lookup. Another: they miss that the problem wants you to handle updates or multiple queries efficiently. StealthCoder will read the constraints and show you whether this is a one-liner mod operation or a range-lookup binary search, letting you code with confidence instead of guessing.
Drill it cold or hedge it with StealthCoder. Either way, don't walk into the OA hoping you remember the trick.
You can drill Get Server Index cold, or you can hedge it. StealthCoder runs invisibly during screen share and surfaces a working solution in under 2 seconds. The proctor sees the IDE. They don't see what's behind it. Made for the candidate who got the OA invite this morning and has 72 hours, not six months.
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Get Server Index FAQ
Is this a modulo hash problem or a binary search problem?+
Most "server index" problems at scale are modulo-based (server_id = hash(key) % num_servers) for simple cases, or binary search if you're looking up ranges. The problem text will tell you whether servers are numbered, have weights, or occupy ranges. Read for that signal first.
What's the most common mistake candidates make on this one?+
Trying to iterate through servers when you should precompute or use math. If there are 1000 servers and 100,000 queries, a linear scan per query will timeout. Jump straight to hashing or binary search on a sorted structure.
Does TikTok ask this as a follow-up or a standalone?+
It's typically standalone. But be ready for a twist: "now handle server failures" or "now servers have different capacities." If that happens, your base solution (hash or binary search) stays the same, just add a filter or weight check.
How do I prepare for this in 24 hours if I'm rusty on hashing?+
Know mod arithmetic cold: hash(key) % n and how collisions don't matter here. If it's binary search, practice finding the leftmost/rightmost position in a sorted array. That's it. Both are 5-minute refreshers.
Is this problem still asked at TikTok, or has it rotated out?+
It was active in February 2024. Server indexing and load balancing are core to TikTok's scale, so variants likely persist. The exact problem might have shifted, but the pattern (mod-based or range lookup) is evergreen.