Difficulty: easy
Category: Greedy Algorithms
A tandem bicycle is a bicycle that's operated by two people: person A and person B. Both people pedal the bicycle, but the person that pedals faster dictates the speed of the bicycle. So if person A pedals at a speed of 5, and person B pedals at a speed of 4, the tandem bicycle moves at a speed of 5 (i.e., tandemSpeed = max(speedA, speedB)`).
You're given two lists of positive integers: one that contains the speeds of riders wearing red shirts and one that contains the speeds of riders wearing blue shirts. Each rider is represented by a single positive integer, which is the speed that they pedal a tandem bicycle at. Both lists have the same length, meaning that there are as many red-shirt riders as there are blue-shirt riders. Your goal is to pair every rider wearing a red shirt with a rider wearing a blue shirt to operate a tandem bicycle.
Write a function that returns the maximum possible total speed or the minimum possible total speed of all of the tandem bicycles being ridden based on an input parameter, fastest. If fastest = true, your function should return the maximum possible total speed; otherwise it should return the minimum total speed.
"Total speed" is defined as the sum of the speeds of all the tandem bicycles being ridden. For example, if there are 4 riders (2 red-shirt riders and 2 blue-shirt riders) who have speeds of 1, 3, 4, 5, and if they're paired on tandem bicycles as follows: [1, 4], [5, 3], then the total speed of these tandem bicycles is 4 + 5 = 9.
Sample Input
redShirtSpeeds = [5, 5, 3, 9, 2]
blueShirtSpeeds = [3, 6, 7, 2, 1]
fastest = trueSample Output
32 // since there are 5 tandem bicycles, and the 5 tandem bicycles that can be formed by combining every rider are `[5, 2], [5, 3], [3, 7], [9, 2], [2, 1]`. The total speed of these tandem bicycles is `5 + 5 + 7 + 9 + 2 = 32`.