//We keep a log of the truck id’s (String) as they enter job sites.

//Given an array of truck id’s, return the top “k” most frequently seen truck ids.

//Example: const list = ["truckId1", "truckId1", "truckId2", "truckId3", "truckId2", "truckId4", "truckId2", "truckId5"], K = 2 return ["truckId1",  "truckId2"]

​

using System;

using System.Linq;

using System.Collections.Generic;

class Program {

  public static void Main (string[] args) {

  TestCase1();

  TestCase2();

  }

​

  public static List<string> MostFrequentTrucks(List<string> truckIds, int topNumTrucks)

  {

  //Fill out this function

  return new List<string>();

  }

​

  public static void TestCase1()

  {

  var truckIds = new List<string>(){

    "truckId1",

    "truckId1",

    "truckId2",

    "truckId3",

    "truckId4",

    "truckId2",

    "truckId5",

    "truckId2"

    };

  var topNumTrucks = 2;

  var result = MostFrequentTrucks(truckIds, topNumTrucks);

  Console.WriteLine(result.Count() == 2);

  Console.WriteLine(result.Contains("truckId1"));

  Console.WriteLine(result.Contains("truckId2"));

  }

​

  public static void TestCase2()

  {

  var truckIds = new List<string>(){

    "truckId1",

    "truckId1",

    "truckId2",

    "truckId3",

    "truckId4",

    "truckId1",

    "truckId2",

    "truckId3",

    "truckId2",

    "truckId2"

    };

  var topNumTrucks = 3;

  var result = MostFrequentTrucks(truckIds, topNumTrucks);

  Console.WriteLine(result.Count() == 3);

  Console.WriteLine(result.Contains("truckId1"));

  Console.WriteLine(result.Contains("truckId2"));

  Console.WriteLine(result.Contains("truckId3"));

  }

}