Merge pull request #2027 from muhazafasa/java-fizz-buzz

added java version of FizzBuzz using sets

Program's_Contributed_By_Contributors/Java_Programs/Misc/FizzBuzzSetImplementation.java

@@ -0,0 +1,65 @@
+// FizzBuzz Java implementation using sets
+// Author: @muhazafasa
+
+import java.util.LinkedList;
+import java.util.HashSet;
+import java.util.Random;
+import java.util.Scanner;
+
+interface Result {
+    String result(int x);
+}
+
+public class FizzBuzzSetImplementation {
+    public static void main(String[] args) {
+        class Pair<X, Y> { 
+            public final X first; 
+            public final Y second; 
+            public Pair(X first, Y second) { 
+                this.first = first; 
+                this.second = second; 
+            } 
+        }
+
+        HashSet<Integer> fizz = new HashSet<Integer>();
+        for (int i = 3; i <= 100; i += 3)
+            fizz.add(i);
+
+        HashSet<Integer> buzz = new HashSet<Integer>();
+        for (int i = 5; i <= 100; i += 5)
+            buzz.add(i);
+
+        HashSet<Integer> fizzBuzz = new HashSet<Integer>(fizz);
+        fizzBuzz.retainAll(buzz);
+
+        HashSet<Integer> rest = new HashSet<Integer>();
+        for (int i = 1; i <= 100; ++i)
+            rest.add(i);
+        rest.removeAll(fizz);
+        rest.removeAll(buzz);
+
+        Result fizzResult = x -> "Fizz";
+        Result buzzResult = x -> "Buzz";
+        Result fizzBuzzResult = x -> "FizzBuzz";
+        Result restResult = x -> String.format("%d", x);
+
+        LinkedList<Pair<HashSet<Integer>, Result>> results = new LinkedList<Pair<HashSet<Integer>, Result>>();
+        results.add(new Pair(fizzBuzz, fizzBuzzResult));
+        results.add(new Pair(fizz, fizzResult));
+        results.add(new Pair(buzz, buzzResult));
+        results.add(new Pair(rest, restResult));
+
+        Random rand = new Random();
+        Scanner scan = new Scanner(System.in);
+
+        while (true) {
+            int number = rand.nextInt(99) + 1;
+            for (var type : results)
+                if (type.first.contains(number)) {
+                    System.out.println(type.second.result(number));
+                    break;
+                }
+            scan.nextLine();
+        }
+    }
+}