Hackerrank - Migratory Birds

Given an array of bird sightings where every element represents a bird type id, determine the id of the most frequently sighted type. If more than 1 type has been spotted that maximum amount, return the smallest of their ids.

Example

There are two each of types and , and one sighting of type . Pick the lower of the two types seen twice: type

.

Function Description

Complete the migratoryBirds function in the editor below.

migratoryBirds has the following parameter(s):

• int arr[n]: the types of birds sighted

Returns

• int: the lowest type id of the most frequently sighted birds

Input Format

The first line contains an integer,

, the size of .
The second line describes as

space-separated integers, each a type number of the bird sighted.

Constraints

It is guaranteed that each type is , , , , or

• .

Sample Input 0

6
1 4 4 4 5 3

Sample Output 0

4

Explanation 0

The different types of birds occur in the following frequencies:

• Type

:

bird

Type

:

birds

Type

:

bird

Type

:

birds

Type

:

• bird

The type number that occurs at the highest frequency is type

, so we print

as our answer.

Sample Input 1

11
1 2 3 4 5 4 3 2 1 3 4

Sample Output 1

3

Explanation 1

The different types of birds occur in the following frequencies:

• Type

: Type : Type : Type : Type : Two types have a frequency of , and the lower of those is type .

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 {

public static int migratoryBirds(List<Integer> arr) {

List<Integer> countList = new ArrayList<>();

Integer[] initialCount = {0,0,0,0,0};

countList.addAll(Arrays.asList(initialCount));

int maxCount = 0;

for (int i = 0; i < arr.size(); i++) {

int currentBirdCount = countList.get(arr.get(i)-1);

countList.set(arr.get(i)-1, ++currentBirdCount);

if(currentBirdCount > maxCount){

maxCount = currentBirdCount;

}

}

return countList.indexOf(maxCount)+1;

}

}

class Solution {

public static void main(String[] args) throws IOException {

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(System.out));

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();

}

}