Given an array of integers arr and two integers k and threshold, return the number of subarrays of size k whose average is greater than or equal to the threshold.
You are given two strings s and t of the same length. In one step, you can choose any character of t and replace it with another character. Return the minimum number of steps to make t an anagram of s.
A social media company wants to analyze tweet activity by counting the number of tweets in given time periods, broken down by minute, hour, or day frequency. Design an API to record tweets and calculate the number of tweets within specific time intervals.
You are given a list of events where each event is represented by a pair [startDay, endDay]. Your task is to find the maximum number of events you can attend, ensuring that you attend only one event per day.