Imagine you're planning a trip using a network of bus routes. Given a set of routes and start/end locations, find the fewest number of buses you must take to reach your destination.

Imagine an empty grid that represents the sea. You are given a sequence of coordinates to add land (islands) to the grid one by one. Determine the number of islands after each addition.

You are given a sorted list of words from an alien language and need to deduce the order of the letters in that language. Determine the alien alphabet order based on the given word sequence.

You're given a square grid of values. Build a quadtree to represent this grid, recursively dividing into quadrants based on whether the values within each quadrant are all the same.

You're a taxi driver trying to maximize your earnings. Given a list of rides with start, end, and tip, find the maximum profit you can make by picking rides that don't overlap.

Find the longest continuous subarray where the absolute difference between any two elements is less than or equal to a given limit. Return the length of this subarray.

You're given an array of integers and a number K. You can negate any number in the array up to K times. Maximize the sum of the array after performing at most K negations.

Given a grid representing land and water, count the number of distinct islands. An island is formed by connected land cells.

You are given equations represented by pairs of variables and their corresponding values. Your task is to evaluate queries based on these equations, determining the value of expressions if possible, or returning -1.0 if not.

Find two numbers in a given array that add up to a specific target value, and return their indices. Essentially, you need to efficiently locate the pair that satisfies the sum requirement.

Given a number, find the closest palindrome to it. You need to return the palindrome that is nearest to the given number, considering both larger and smaller palindromes.

Find the kth smallest value in a given Binary Search Tree. Return the node's value that holds this smallest element.

You are given a board of characters and a list of words. Find all the words from the list that can be formed by traversing adjacent cells on the board.

You're given daily stock prices. Find the maximum profit you can make by buying and selling the stock once. You must buy before you sell.

Calculate a new array where each element is the product of all numbers in the original array, excluding the number at that index. Do this efficiently without using division.

Determine if a given word can be constructed from letters in a 2D board, where letters can be used horizontally or vertically. Each letter can only be used once in the word.

You're given a sorted array of integers. Return a new array containing the squares of each number, also sorted in non-decreasing order.

Design a data structure that acts as a Least Recently Used (LRU) cache. Implement methods to get and put key-value pairs, evicting the least recently used entry when the cache is full.

Given a sequence of words and a line width, format the text to fit within the specified width. You must justify the text, distributing extra spaces evenly between words.

Design a calendar system. You need to implement a function to book new events, but avoid double booking (overlapping events).