Tech Interview Questions

Coding & AlgorithmsLinked ListsTwo Pointers & Sliding Window

Remove a Linked Node by Its Distance from the Tail

Problem Given the head of a singly linked list and an integer n, remove the node that is n positions from the tail, counting the tail as position 1. R...

55 people solved

Machine Learning EngineerIntern

Length of the Longest Run of One Repeated Character in a String

Given a string, return the length of its longest run: the longest stretch of consecutive positions that all hold the same character. Function Signatur...

Coding & AlgorithmsArrays & Strings

57 people solved

Oct 14, 2026

GoogleAmazonMicrosoft

Compact a Sorted Array into Its Distinct Prefix

Problem The integer array nums is sorted in nondecreasing order. Modify it in place so that each distinct value appears once in the beginning of the s...

Coding & AlgorithmsString Algorithms

Count Windows That Follow an Increase, Equal, Decrease Pattern

You are given an integer array numbers and an array pattern whose values are each 1, 0 or -1. Let m = len(pattern). A window of m + 1 consecutive elem...

67 people solved

Oct 16, 2026

GoogleBloombergAmazon

Medium

Coding & AlgorithmsTwo Pointers & Sliding WindowSorting

Choose the Closest Three-Position Sum

Problem Given the integer array values and the integer target, choose three array positions whose sum is nearest to target. The three positions must b...

51 people solved

Confluent

Software EngineerNew Grad

Count Length-k Windows That Are Strictly Increasing

Given an integer array nums and an integer k, count the contiguous windows of exactly k elements whose values are strictly increasing from left to rig...

Software EngineerNew Grad

Choose an Offset for Compressing Clustered Integers with Outliers

Most integers in a dataset are concentrated in a narrow range, with a few outliers. Choose an offset that reduces storage, and explain how a sliding w...

Software Engineering FundamentalsTwo Pointers & Sliding WindowSorting

Return the k Smallest Squares of a Sorted Integer Array in Order

You are given an integer array nums sorted in non-decreasing order, which may contain negative numbers, and an integer k. Return the k smallest values...

Coding & AlgorithmsBinary SearchTwo Pointers & Sliding Window

128 people solved

Sep 29, 2026

GoogleAmazonBloomberg

Hard

Coding & AlgorithmsTwo Pointers & Sliding WindowArrays & Strings

Find Every Concatenation Starting Index

Problem You receive a string text and an array of strings pieces. Every piece has the same positive length. Return every zero-based starting index in ...

37 people solved

Bnsf

Medium

Software EngineerSenior+

Minimum Station Tracks for a Schedule of Train Arrivals and Departures

A railway station must handle a schedule of trains. Each train occupies one station track from the moment it arrives until the moment it departs, and ...

Coding & AlgorithmsIntervals & Scheduling

Shortest Contiguous Team From Each Start Covering K Distinct Subjects

A teacher is taking a line of contestants, called talents, to a series of competitions. Each talent is strong in exactly one subject, given as an inte...

Coding & AlgorithmsGreedyTwo Pointers & Sliding Window

15 people solved

Nov 7, 2026

Hard

Software Engineer Locked

Fewest Subsequences of a Source String That Concatenate to a Target String

Given a source string and a target string, return the fewest subsequences of the source whose concatenation equals the target, or -1 when the target c...

277 people solved

Sep 19, 2026

GoogleAmazonBloomberg

Remove Chosen Values from an Array Prefix

Problem Given the integer array nums and integer val, remove every occurrence of val in place. Return the number k of elements whose values differ fro...

Software Engineering FundamentalsTwo Pointers & Sliding WindowTesting & Quality

Detect Security Attacks in Text Logs Using Sliding-Window Rules

You are given a large collection of text-format log lines describing network connections, and a set of rules that define security attacks. Write a pro...

Maximum of Each Length-k Window in an Integer Array

Given an integer array nums and a window length k, slide a window of exactly k consecutive elements from the left end of the array to the right end, o...

Coding & AlgorithmsTwo Pointers & Sliding WindowStacks & Queues

Shortest Subarray Whose Distinct-Value Sum Reaches a Target

Given an array of positive integers nums and a positive integer target, return the length of the shortest contiguous subarray whose distinct sum is at...