You are given a string s consisting of lowercase English letters. The task is to rearrange the characters of the string such that no two adjacent characters are the same. Return any valid rearrangement of the string, or return an empty string if it is not possible to rearrange the characters in such a way.
You are given a sorted array of prime numbers and the number 1. You need to find the k-th smallest fraction formed by considering all possible fractions arr[i] / arr[j] where i < j. Return the k-th smallest fraction as an array of two integers, where arr[i] is the numerator and arr[j] is the denominator.
You are given a number of cities and a list of flights between them. Each flight has a price and connects two cities. You need to find the cheapest route from a given source city to a destination city with at most a certain number of stops. If no such route exists, return -1.
You are tasked with simulating an exam room where students will choose seats based on a strategy that maximizes their distance from the closest person already seated. If multiple seats have the same distance, the student will choose the seat with the smallest index. Additionally, students can leave the room, freeing up their seats.
Given an array of points on a 2D plane, find the k closest points to the origin (0, 0) based on Euclidean distance. If multiple points have the same distance, any order is acceptable.
In this problem, we have an array of integers representing stones. Each stone has a weight, and on each turn, we choose the two heaviest stones, smash them together, and apply the following rules: If the two stones have the same weight, both are destroyed. If they have different weights, the stone with the smaller weight is destroyed, and the stone with the larger weight gets reduced by the smaller stone’s weight. The process continues until at most one stone remains. Your task is to return the weight of the last remaining stone. If no stones are left, return 0.
