Finding the k-largest values in a set of data - Assume you are given a sequence of values. We do not know how many elements there are in this sequence. In fact, there could be infinitely many. Implement the class KBestCounter> that keeps track of the k-largest elements seen so far in a set of data. The class should have two methods:
public void count(T x) - process the next element in the set of data. This operation should run in the at worst O(log k) time.
public List kbest() - return a sorted (largest to smallest) list of the k largest elements. This should run in O(k log k) time. The method should restore the priority queue to its original state after retrieving the klargest elements. If you run this method twice in a row, it should return the same values.
Use a Priority Queue to implement this functionality. We suggest using the built-in java. util. PriorityQueue, which implements a min-heap for you. You should never have more than k elements inserted into the Priority Queue at any given time.
import java. util. PriorityQueue;
public class KBestCounter> {
PriorityQueue heap;
int k;
public KBestCounter(int k) {
//todo
}
public void count(T x) {
//todo
}
public List kbest() {//
todo
}
}