Find First Unique Character From a Stream of Characters Problem Given a string A denoting a stream of lowercase alphabets. You have to make new string B. B is formed such that we have to find first non-repeating character each time a character is inserted to the stream and append it at the end to B. If no non-repeating character is found then append ’#’ at the end of B. ...
Problem Design a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element. Implement KthLargest class: KthLargest(int k, int[] nums) Initializes the object with the integer k and the stream of integers nums. int add(int val) Appends the integer val to the stream and returns the element representing the kth largest element in the stream. Class Skeleton: ...
Problem Given a stream of elements too large to store in memory, pick a random element from the stream with uniform probability. Solution This is a classic problem known as Reservoir Sampling. The goal is to randomly select an element from a large stream of data with uniform probability, even when the entire stream cannot be stored in memory. Introduction to Problem Reservoir sampling, often referred to as Algorithm R as described by Jeffrey Vitter in Random Sampling with a Reservoir, is a widely used technique in data processing. It allows for the random selection of k samples from a set S containing n items, where n is very large or unknown. Each of the chosen k items forms a “reservoir,” ensuring that every item is selected with an equal probability of 1/n. ...
Problem Given a document (or stream) of words. Find the top k most frequent words in the document (or stream). OR Given an array of strings words and an integer k, return the k most frequent strings. Return the answer sorted by the frequency from highest to lowest. Sort the words with the same frequency by their lexicographical order. Examples Example 1: Input: words = ["i","love","leetcode","i","love","coding"], k = 2 Output: ["i","love"] Explanation: "i" and "love" are the two most frequent words. Note that "i" comes before "love" due to a lower alphabetical order. ...