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

Solution 1 (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();
    }
}

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;
    }
}