Divisible Sum Pairs.java

/* Problem link
https://www.hackerrank.com/challenges/three-month-preparation-kit-divisible-sum-pairs/problem?isFullScreen=true&h_l=interview&playlist_slugs%5B%5D=preparation-kits&playlist_slugs%5B%5D=three-month-preparation-kit&playlist_slugs%5B%5D=three-month-week-one
*/

//Solution

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 'divisibleSumPairs' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts following parameters:
     *  1. INTEGER n
     *  2. INTEGER k
     *  3. INTEGER_ARRAY ar
     */

    public static int divisibleSumPairs(int n, int k, List<Integer> ar) {
    // Write your code here
    int count=0;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(i<j)
                if((ar.get(i)+ar.get(j))%k==0)
                    count++;
        }
    }
    return count;

    }

}

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")));

        String[] firstMultipleInput = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");

        int n = Integer.parseInt(firstMultipleInput[0]);

        int k = Integer.parseInt(firstMultipleInput[1]);

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

        int result = Result.divisibleSumPairs(n, k, ar);

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

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