updated readme

General Programming/Basic Programming/Between Two Sets/Solution.java

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+//     Author: Rodney Shaghoulian
+//     Github: github.com/rshaghoulian
+// HackerRank: hackerrank.com/rshaghoulian
+
+import java.util.Scanner;
+import java.util.Arrays;
+
+public class Solution {
+    public static void main(String [] args) {
+        /* Save input */
+        Scanner scan = new Scanner(System.in);
+        int n = scan.nextInt();
+        int m = scan.nextInt();
+        int [] arrayA = new int[n];
+        for (int i = 0; i < n; i++) {
+            arrayA[i] = scan.nextInt();
+        }
+        int [] arrayB = new int[m];
+        for (int i = 0; i < m; i++) {
+            arrayB[i] = scan.nextInt();
+        }
+        scan.close();
+        
+        /* Find LCM of arrayA. Find GCD of arrayB */
+        int A_LCM = lcm(arrayA);
+        int B_GCD = gcd(arrayB);
+        
+        /* Calculate # of integers "between" arrayA and arrayB */
+        int count = (B_GCD % A_LCM == 0) ? numDivisors(B_GCD / A_LCM) : 0;
+        System.out.println(count);
+    }
+    
+    private static int gcd(int a, int b) { // Euclid's GCD Algorithm
+        while (b != 0) {
+            int temp = b;
+            b = a % b;
+            a = temp;
+        }
+        return a;
+    }
+    
+    private static int lcm(int a, int b) {
+        return (a * b) / gcd(a, b);
+    }
+    
+    /* Uses Java 8 streams for better parallelization of code */
+    private static int gcd(int [] array) {
+        return Arrays.stream(array).reduce(array[0], (a, b) -> gcd(a, b));
+    }
+
+    /* Uses Java 8 streams for better parallelization of code */
+    private static int lcm(int [] array) {
+        return Arrays.stream(array).reduce(array[0], (a, b) -> lcm(a, b));
+    }
+    
+    private static int numDivisors(int n) {
+        int count = 0;
+        int sqrt = (int) Math.sqrt(n);
+        for (int i = 1; i <= sqrt; i++) {
+            if (n % i == 0) { // if "i" is a divisor
+                count += 2;   // account for both divisors
+            }
+        }
+        /* If sqrt is a divisor, we should only count it once */
+        if (sqrt * sqrt == n) {
+            count--;
+        }
+        return count;
+    }
+}