You are given n baskets with distinct positions, and m balls to place in them. The magnetic force between two balls at positions x and y is |x - y|. The goal is to place the balls into baskets such that the minimum magnetic force between any two balls is maximized.
Given a 2D grid of characters, find if there exists a cycle where the same character repeats in the grid. A cycle is defined as a path where a character appears 4 or more times, forming a loop that starts and ends at the same cell. The cycle must consist of adjacent cells, and you are not allowed to revisit the previous cell.
You and two friends are given 3n piles of coins, and in each step, three piles are chosen. Alice always picks the pile with the most coins, you pick the second largest pile, and your friend Bob picks the remaining pile. Repeat this process until all piles are picked. Your goal is to maximize the total number of coins you can collect.
You are given a permutation of integers from 1 to n, where each integer represents a position in a binary string of size n that is initially filled with zeros. At each step, you will flip the bit at the position specified by the current element of the array. You are also given an integer m, and your task is to determine the latest step at which there exists a contiguous substring of exactly m ones in the binary string.
Given an array of integers, your task is to find the maximum length of a contiguous subarray where the product of all its elements is positive. The product of a subarray is considered positive if the result of multiplying all elements of the subarray results in a positive number.