Given a list of historic stock prices,write a function that tells when you should have bought and sold to make the most profit. You can only buy and sell once. Example input: Goal:Return the best buy date and best sell date to maximize profit. One pass: track the lowest price so far, and at each…

Imagine you have a Twitter-style social network.Each post can have multiple tags. Your task: Return the top X most frequent tags used by your friends and your friends-of-friends. In other words, starting from a given user: Example (conceptual): If X = 2, output: Use BFS up to depth 2 to collect friends and friends-of-friends.Count tag…

I own a parking garage that provides valet parking service. There are three types of parking spots: Cars also come in three sizes: Rules: You receive a stream of parking events.Each event is either: Your system must assign a valid spot on arrival and free the spot on departure. Example input (conceptual): You need to…

You are given an integer array coins representing coin denominations, and an integer amount representing a total amount of money. Return the fewest number of coins needed to make up the given amount.If it is not possible, return -1. You may use unlimited coins of each denomination. Example 1 Example 2 Use DP:dp[x] = min(dp[x],…

You are given an array of integers representing the amount of money stored in each house.The houses are arranged in a line, and you cannot rob two adjacent houses. Return the maximum amount of money you can rob without ever robbing two adjacent houses. Example (Explanation: choose non-adjacent houses so the sum is maximized.) Use…

Amazon has web server logs from multiple hosts.Each log entry consists of: Example (conceptual): We want to find the 3-page pattern that is visited most frequently across all sessions. In the example, the sequence <cart, checkout, help> appears twice, so it is the most frequent 3-page pattern. Given logs in the form: Return the 3-page…

Convert a number to an Excel column, and convert an Excel column back to a number. In Excel, columns are labeled as: You are asked to implement two functions: You may assume: The VOprep team has long accompanied candidates through various major company OAs and VOs, including Google, Amazon, Citadel, SIG, providing real-time voice assistance, remote practice,…

Implement the Linux find command as an API. Your API should support searching for files that match: Assume the filesystem is represented as a tree-like structure of directories and files. Your job:Design and implement a find-like API that searches the file system and returns all files that satisfy the given filters. Do a DFS traversal…

You are given a (potentially large) list of words.Some words are compound words, meaning they are composed of two or more words that also exist in the same list. Example word list:[rockstar, rock, star, rocks, tar, stars, rockstars, super, highway, high, way, superhighway] Goal:Identify all combinations where a word can be decomposed into two or…

Given an array of integers, find the index of a local minimum. A local minimum is defined as an element that is strictly smaller than its neighbors.Formally: You may assume: Goal:Return the index of one such local minimum. Example: You must return the index of any element that is strictly smaller than both neighbors.Since adjacent…

Implement the function pow(x, n), which calculates x^n.Note that you cannot use any built-in functions that directly implement pow. Examples: Key Ideas: This approach tests understanding of recursion, divide and conquer, and edge case handling (e.g. negative powers, floating-point base). The VOprep team has long accompanied candidates through various major company OAs and VOs, including SnowFlake, Google,…