You are given the positions of houses and heaters along a horizontal line. Your task is to find the minimum radius required for the heaters so that all houses are within the heater’s warm radius.
You are given an array of non-overlapping axis-aligned rectangles. Each rectangle is represented by its bottom-left and top-right corner. Your task is to design a system that can pick a random integer point from the space covered by one of the given rectangles. A point on the perimeter of a rectangle is considered inside the rectangle.
You are given a 0-indexed array of positive integers w, where w[i] describes the weight of the ith index. You need to implement the function pickIndex() which randomly picks an index in the range [0, w.length - 1] (inclusive), and the probability of picking index i is w[i] / sum(w).
Given an array of integers nums and an integer k, return the number of unique k-diff pairs in the array. A k-diff pair is a pair of integers (nums[i], nums[j]) where the absolute difference between the values of the pair is k, and i != j.
You are given a sorted array where every element appears exactly twice, except for one element which appears only once. Find and return the single element that does not have a pair.
Given an array of integers, return the number of triplets that can form a valid triangle. A valid triangle is formed when the sum of any two sides is greater than the third side.
