해커랭크 Hackerrank ) Migratory Birds

https://www.hackerrank.com/challenges/migratory-birds/problem?isFullScreen=true 

Migratory Birds | HackerRank

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {

    /*
     * Complete the 'migratoryBirds' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts INTEGER_ARRAY arr as parameter.
     */

    public static int migratoryBirds(List<Integer> arr) {
        Map<Integer,Integer> mapList = new HashMap<Integer,Integer>() {{
            put(1,0);
            put(2,0);
            put(3,0);
            put(4,0);
            put(5,0);
        }};
        for (int i = 0; i < arr.size(); i++) {
            mapList.put(arr.get(i),mapList.get(arr.get(i)+1));
        }
        int countList[] = new int[5];
        for (int i : countList) {
          countList[i] = mapList.get(i);  
        }
        Arrays.sort(countList);
        
        return countList[0];
    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int arrCount = Integer.parseInt(bufferedReader.readLine().trim());

        List<Integer> arr = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
            .map(Integer::parseInt)
            .collect(toList());

        int result = Result.migratoryBirds(arr);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}