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: 421 ms):
import java.io.*;
import java.util.*;

public class GorillaExam {
    static int mint = (int) 1e6 + 7;
    static int mod_i = (int) 1e9 + 7;
    static long mod_l = (long) 1e12 + 7;
    public static void main(String[] args) throws IOException {
        //Scanner sc = new Scanner(System.in);
        Kattio io = new Kattio(System.in, System.out);
        int t = io.getInt();
        for (int i = 0; i < t; i++) {
            int n = io.getInt();
            int k = io.getInt();
            Map<Integer, Integer> hm = new TreeMap<>();
            for (int j = 0; j < n; j++) {
                int temp = io.getInt();
                hm.put(temp, hm.getOrDefault(temp, 0)+1);
            }
            List<Integer> cnt = new ArrayList<>(hm.values());
            Collections.sort(cnt);
//            System.out.println(cnt);
            for(int j=0;j<cnt.size();j++){
//                System.out.println(cnt.get(j)+" "+k);
                int affect = Math.min(cnt.get(j), k);
                cnt.set(j, cnt.get(j)-affect);
                k-=affect;
            }
//            System.out.println(cnt);
            int ans = 0;
            for (int val: cnt) {
                if(val!=0) ans++;
            }
//            System.out.println(ans);
            System.out.println(ans==0?1:ans);
        }
        io.close();
    }
}
class Pair {
    int x;
    long y;
    public Pair(int x, long y) {
       this.x = x;
       this.y = y;
    }
}
class Tuple {
    int x;
    long y;
    int z;
    public Tuple(int x, long y, int z) {
       this.x = x;
       this.y = y;
       this.z = z;
    }
}
class Kattio extends PrintWriter {
    public Kattio(InputStream i) {
        super(new BufferedOutputStream(System.out));
        r = new BufferedReader(new InputStreamReader(i));
    }
    public Kattio(InputStream i, OutputStream o) {
        super(new BufferedOutputStream(o));
        r = new BufferedReader(new InputStreamReader(i));
    }


    public boolean hasMoreTokens() {
        return peekToken() != null;
    }

    public int getInt() {
        return Integer.parseInt(nextToken());
    }

    public double getDouble() {
        return Double.parseDouble(nextToken());
    }

    public long getLong() {
        return Long.parseLong(nextToken());
    }

    public String getWord() {
        return nextToken();
    }


    private BufferedReader r;
    private String line;
    private StringTokenizer st;
    private String token;

    private String peekToken() {
        if (token == null)
            try {
                while (st == null || !st.hasMoreTokens()) {
                    line = r.readLine();
                    if (line == null) return null;
                    st = new StringTokenizer(line);
                }
                token = st.nextToken();
            } catch (IOException e) { }
        return token;
    }

    private String nextToken() {
        String ans = peekToken();
        token = null;
        return ans;
    }
}