BetweenTwoSets.java

//https://www.hackerrank.com/challenges/between-two-sets/problem?isFullScreen=true
//Check out Study Algorithms on youtube and github! Super helpful!! https://github.com/nikoo28/java-solutions
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 'getTotalX' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts following parameters:
     *  1. INTEGER_ARRAY a
     *  2. INTEGER_ARRAY b
     */

    public static int getGCD(int n1, int n2) {
        if (n2==0) {
            return n1;
        }
        return getGCD(n2,n1 % n2);
    }
    
    public static int getLCM(int n1, int n2) {
        if (n1==0 || n2==0) {
            return 0;
        } else {
            int gcd = getGCD(n1, n2);
            return Math.abs(n1 * n2) / gcd;
        }
    }

    public static int getTotalX(List<Integer> a, List<Integer> b) {
        int result = 0;
        
        int lcm = a.get(0);
        for(Integer integer : a) {
            lcm = getLCM(lcm, integer);
        }
        
        int gcd = b.get(0);
        for(Integer integer : b) {
            gcd = getGCD(gcd, integer);
        }
        
        int multiple = 0;
        while (multiple <= gcd) {
            multiple += lcm;
            
            if (gcd % multiple == 0)
            result ++;
        }
        return result;
    }

}

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 m = Integer.parseInt(firstMultipleInput[1]);

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

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

        int total = Result.getTotalX(arr, brr);

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

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