TikTok interview questions

Remove Duplicate Letters

Remove duplicate letters from s so each character appears exactly once and the resulting string is the smallest possible in lexicographic order. This is solved…

Companies: TikTok

Greedy · Monotonic Stack · Stack · String

Reverse Linked List

Companies: TikTok, Apple

Linked List · Recursion

Reverse Nodes in k-Group

Given the head of a linked list and an integer k, reverse the nodes of the list k at a time and return the modified…

Companies: TikTok, Adobe, Microsoft

Linked List · Recursion

Rotate Array

Rotate an integer array to the right by k steps (k may exceed the array length), effectively moving each element to index (i+k) mod n…

Companies: TikTok, Apple, Microsoft, Nutanix

Array · Math · Two Pointers

Search in Rotated Sorted Array

Given an ascending array of distinct integers that has been rotated at an unknown pivot, return the index of a target value (or -1 if…

Companies: TikTok, Amazon, Expedia, Google +3

Array · Binary Search

Serialize and Deserialize N-ary Tree

Design algorithms to serialize an N-ary tree into a single string and deserialize it back, preserving node values and the arbitrary number and order of…

Companies: TikTok, Apple, Bloomberg, Rubrik

Breadth-First Search · Depth-First Search · String · Tree

Single-Threaded CPU

Given tasks with enqueue and processing times, return the order a single-threaded CPU will process them when it always picks the available task with the…

Companies: TikTok, DoorDash

Array · Heap (Priority Queue) · Sorting

Spiral Matrix

Traverse the m×n matrix in clockwise spiral order (right, down, left, up) and return the elements in that sequence. The core challenge is managing changing…

Companies: TikTok, Capital One, Liveramp, Meta +1

Array · Matrix · Simulation

Subarray Sums Divisible by K

Count the number of contiguous subarrays whose sum is divisible by k; this reduces to counting pairs of prefix sums with the same remainder modulo…

Companies: TikTok

Array · Hash Table · Prefix Sum

Talk about your past projects

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Tell me about a time you had a disagreement with a teammate.

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Tell us about a project you worked on

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Two Sum

Given an array of integers and a target, return the indices of two distinct elements whose values sum to the target (exactly one valid solution…

Companies: TikTok, Amazon, Apple, Bloomberg +13

Array · Hash Table

When prioritize precision vs recall

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you can focus on the top frequency in LC

Companies: TikTok