Problem: 2057B - Gorilla and the Exam
Language: java

Solution 1 (runtime: 390 ms):
import java.util.*;
import java.io.*;

public class GorillaandtheExam {

    public static void main(String[] args) {
        FastReader sc = new FastReader();
        int t = sc.nextInt();
        while (t-- > 0) {
            int n = sc.nextInt();
            int k = sc.nextInt();

            HashMap<Integer,Integer> map=new HashMap<>();
            int[] arr = new int[n];
            arr[0]=sc.nextInt();
            int maxVal=arr[0];
            map.put(arr[0],map.getOrDefault(arr[0],0)+1);
            for (int i = 1; i < n; i++) {
                arr[i] = sc.nextInt();
                map.put(arr[i],map.getOrDefault(arr[i],0)+1);
                if(map.get(arr[i])>map.get(maxVal)){
                    maxVal=arr[i];
                }
            }

            HashMap<Integer,Integer> sortedMap=new HashMap<>();
            sortedMap=sortMap(map);

//            System.out.println(sortedMap);
//            System.out.println(maxVal);

            int count=map.size();
            for(Map.Entry<Integer,Integer> entry:sortedMap.entrySet()){
                if(count==1) break;
                int value=entry.getValue();
                if(k>=value){
                    k-=value;
                    count--;
                }
                else break;


            }

            System.out.println(count);
        }
    }

    public static HashMap<Integer,Integer> sortMap(HashMap<Integer,Integer> map){

        List<Map.Entry<Integer, Integer>> entryList = new ArrayList<>(map.entrySet());

        // Step 3: Sort the list by values
        entryList.sort(Map.Entry.comparingByValue());

        // Step 4: Create a LinkedHashMap to maintain the sorted order
        LinkedHashMap<Integer, Integer> sortedMap = new LinkedHashMap<>();
        for (Map.Entry<Integer, Integer> entry : entryList) {
            sortedMap.put(entry.getKey(), entry.getValue());
        }

//        // Display the sorted map
//        for (Map.Entry<Integer, Integer> entry : sortedMap.entrySet()) {
//            System.out.println(entry.getKey() + " -> " + entry.getValue());
//        }

        return sortedMap;
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine().trim();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}

Solution 2 (runtime: 562 ms):
// Gorilla and the exam

import java.util.*;

public class _2057B {
    public static void sovle(int k, int arr[]) {
        Arrays.sort(arr);
        List<Integer> cnt = new ArrayList<>();
        cnt.add(1);
        for (int i = 1; i < arr.length; i++) {
            if (arr[i] == arr[i - 1]) {
                cnt.set(cnt.size() - 1, cnt.get(cnt.size() - 1) + 1);
            } else {
                cnt.add(1);
            }
        }

        Collections.sort(cnt);
        int m = cnt.size();
        for (int i = 0; i < m - 1; i++) {
            if (cnt.get(i) > k) {
                System.out.println(m - i);
                return;
            }
            k -= cnt.get(i);
        }
        System.out.println(1);
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        while (t > 0) {
            int n = sc.nextInt();
            int k = sc.nextInt();

            int arr[] = new int[n];

            for (int i = 0; i < n; i++) {
                arr[i] = sc.nextInt();
            }

            sovle(k, arr);

            t--;
        }
        sc.close();
    }
}