Problem Statement: Build a service/system that can support defining and running jobs on a schedule. Requirements: Summary (what to design & key choices) Goal: A horizontally scalable, highly reliable job orchestration service (cron-as-a-service). Core components Key APIs Data model (simplified) Scheduling strategy Failure & SLA handling Scaling The VOprep team has long accompanied candidates through various major…

Input (stdin)An order message is a request to trade shares: New fields: Order rules ✅ Output (stdout) After receiving an order at time T, emit prints: Following constraints: ✅ Example Output Explanation: ✅ Summary This problem simulates an execution algorithm constrained by: ✅ Trailing-minute external traded volume✅ Participation rate limits (PR)✅ Expiration of orders✅ Partial…

Input (stdin)The program reads the input line by line. Each line must be one of the following message types: • A print represents a trade that took place on the exchange: • A volume check is a request to report the total traded quantities of a security in the preceding minute, as well as its…

You have been tasked with creating an exchange where traders can buy and sell Sea Shells. The program reads incoming orders and emits trades. Input (stdin) – the input is a stream of limit orders. Each line is a separate order identified by its line number (starting at 1), with space-delimited fields: Examples: Processing orders…

A Kac ring is a dynamical system defined as follows: Part 1: Implement a Kac ring with the following interface: Brief summary: Simulate a circular system where balls move one step each tick and flip color only when leaving a marked slot. Build an object with step() and an O(1) color() that returns (white−black)/N(white –…

The program reads the input line by line from stdin.Each line is exactly one of the following message types: Fields (space-delimited): An order is: Output For each volume-check for security S at time T, emit exactly one line: Where: A volume-check response must be printed immediately before reading the next input line. For each order…

Ski season is approaching! You work at a ski resort and must ensure the slopes are fully covered with snow. You have a slope with indices from 0…N, and a collection of snow-making machines installed along the slope.Each machine is a tuple (index, range) meaning the machine sits at index and can cover the slope…

Problem (verbatim) Design a data structure that supports insert, delete, search, and getRandom in constant time. Use a dynamic array + hash map (value → index). The VOprep team has long accompanied candidates through various major company OAs and VOs, including Tiktok, Google, Amazon, Citadel, SIG, providing real-time voice assistance, remote practice, and interview pacing reminders to…

Given an array of positive integers nums and an integer k,return true if nums has a continuous subarray whose sum equals k. Examples: Since all numbers are positive, we can use a sliding window: This works in O(n) because the two pointers only move forward. The VOprep team has long accompanied candidates through various major company OAs…

You are given a string s.You can convert s to a palindrome by adding characters in front of it.Return the shortest palindrome you can form by performing this transformation. Input:s = “aacecaaa” Output:”aaacecaaa” The task is to create the shortest palindrome by adding characters only to the front of the given string. Main idea: Optimal…

Given a string s, return true if it is a palindrome, or false otherwise. Input:s = “aba” Output:true This problem checks whether a string is a palindrome, meaning it reads the same forward and backward. Typical approach: Runs in O(n) time and O(1) space (two-pointer approach). The VOprep team has long accompanied candidates through various major company…

A unique character is one that appears only once in a string.Given a string consisting of lowercase English letters only, return the index of the first occurrence of a unique character in the string using 1-based indexing.If the string does not contain any unique character, return -1. Example:s = “statistics”The unique characters are [a, c],…

Parentheses strings are strings containing only the characters ‘(‘ and ‘)’.A parentheses string is considered balanced when its opening parentheses align with its closing parentheses.For example, “()” and “(())” are balanced, while “)(“, “())(” are not. Given a string consisting of the same number of opening and closing parentheses, determine the minimum number of character…

You are running a car dealership and currently have 2 employees.We are going to be building a basic function to deal with customers booking appointments with your employees. You have the following constraints: Implement a DealershipScheduler class with the following method: Return true if you can book an appointment for these times, and false if…

You’re building a daily calendar app and need to display all of the day’s events in the right location on the screen, but it needs to be given a bounding box.We need to take a list of events happening that day and produce a list of bounding boxes to be drawn. An event has: Example…

Problem statement（题目原文）Given: What is the result of each of the following statements? Brief idea Know == performs coercion (string → number), === doesn’t; + concatenates when a string is involved; unary + coerces to number. The VOprep team has long accompanied candidates through various major company OAs and VOs, including Microsoft Google, Amazon, Citadel, SIG, providing real-time…

Problem statementImagine you’re working on a language which only supports Stack, but you need a Queue functionality to fulfill the requirement. Design a queue that supports standard operations using stacks. Brief idea (EN)Use two stacks: in and out. The VOprep team has long accompanied candidates through various major company OAs and VOs, including Microsoft Google, Amazon, Citadel,…

Design a simulation for a card game. This game is playable by 2 or more playersand consists of four phases performed in order: shuffle, deal, exchange, and score. Deck of cards: The VOprep team has long accompanied candidates through various major company OAs and VOs, including Microsoft Google, Amazon, Citadel, SIG, providing real-time voice assistance, remote practice,…

Description The 8 Puzzle is a sliding block game played on a 3×3 grid containing 8 numbered tiles (from 1 to 8) and one empty space represented by 0. The objective is to rearrange the tiles into a specific goal configuration by sliding them one at a time.Only tiles adjacent to the empty space (0)…

An integer array “original” is transformed into a doubled array “changed” by appending twice the value of every element in “original”, and then randomly shuffling the resulting array.Given an array “changed”, return “original” if “changed” is a doubled array. If “changed” is not a doubled array, return an empty array. The elements in “original” may…