You are given a list of integers where each integer represents a student’s happiness threshold. The task is to determine the number of ways to select a group of students so that all students in the group remain happy.
You are running a company that manufactures alloys using various types of metals. There are n different metal types available, and you have k machines that can be used to create alloys. Each machine requires a specific amount of each metal type to create an alloy. The i-th machine requires composition[i][j] units of metal type j. You have stock[i] units of metal type i, and purchasing one unit of metal type i costs cost[i] coins. Your task is to maximize the number of alloys you can produce while staying within a budget of budget coins. Each alloy must be made using the same machine.
You are given an array heights representing the number of bricks in n consecutive towers. Your task is to remove some bricks to form a mountain-shaped tower arrangement. In this arrangement, the tower heights are non-decreasing, reaching a maximum peak value with one or multiple consecutive towers and then non-increasing. Return the maximum possible sum of heights of a mountain-shaped tower arrangement.
You are given an array maxHeights of n integers. Your task is to build n towers in the coordinate line where the height of the i-th tower is between 1 and maxHeights[i]. The configuration is beautiful if the heights form a mountain array, where heights increase to a peak and then decrease afterward. Return the maximum possible sum of the heights of a beautiful tower configuration.
You are given an array nums containing positive integers and an integer k. In each operation, you can remove the last element from the array and add it to your collection. Your task is to determine the minimum number of operations needed to collect all elements from 1 to k (inclusive).