union and intersection

Hashing/unionandIntersection.java

@@ -0,0 +1,35 @@
+package Hashing;
+
+import java.util.*;
+
+public class unionandIntersection {
+    public static void main(String[] args) {
+        int arr1[] = { 7, 3, 9 };
+        int arr2[] = { 6, 3, 9, 2, 9, 4 };
+        HashSet<Integer> set = new HashSet<>();
+
+        // Union
+        for (int i = 0; i < arr1.length; i++) {
+            set.add(arr1[i]);
+        }
+
+        for (int i = 0; i < arr2.length; i++) {
+            set.add(arr2[i]);
+        }
+        System.out.println("Union : " + set.size());
+
+        // intersection
+        int count = 0;
+        set.clear();
+        for (int i = 0; i < arr1.length; i++) {
+            set.add(arr1[i]);
+        }
+        for (int i = 0; i < arr2.length; i++) {
+            if (set.contains(arr2[i])) {
+                count++;
+                set.remove(arr2[i]);
+            }
+        }
+        System.out.println("Intersection : "+count);
+    }
+}