Add Ex 20.10

Author: jsquared21

Exercise_20/Exercise_20_10/Exercise_20_10.class

@@ -0,0 +1,49 @@
+/**************************************************************************
+* (Perform set operations on priority queues) Create two priority queues, *
+* {"George", "Jim", "John", "Blake", "Kevin", "Michael"} and              *
+* {"George", "Katie", "Kevin", "Michelle", "Ryan"}, and find their union, *
+* difference, and intersection.                                           *
+**************************************************************************/
+import java.util.*;
+
+public class Exercise_20_10 {
+	public static void main(String[] args) {
+		// Create two priority queues
+		PriorityQueue<String> queue1 = new PriorityQueue<>(Arrays.asList(
+			"George", "Jim", "John", "Blake", "Kevin", "Michael"));
+
+		PriorityQueue<String> queue2 = new PriorityQueue<>(Arrays.asList(
+			"George", "Katie", "Kevin", "Michelle", "Ryan"));
+
+		// Display the two sets and union, difference, and intersection
+		System.out.println("Set1: " + queue1);
+		System.out.println("Set2: " + queue2);
+		System.out.println("Union of sets: " + union(queue1, queue2));
+		System.out.println("Difference of sets: " + difference(queue1, queue2));
+		System.out.println("Intersection of sets: " + intersection(queue1, queue2));
+	}
+
+	/** Method returns the union of two sets */
+	private static <T> PriorityQueue<T> union(
+			PriorityQueue<T> set1, PriorityQueue<T> set2) {
+		PriorityQueue<T> union = new PriorityQueue<>(set1);
+		union.addAll(set2); 
+		return union;
+	} 
+
+	/** Method returns the difference of two sets */
+	private static <T> PriorityQueue<T> difference(
+			PriorityQueue<T> set1, PriorityQueue<T> set2) {
+		PriorityQueue<T> difference = new PriorityQueue<>(set1);
+		difference.removeAll(set2);
+		return difference;
+	}
+
+	/** Method returns the intersection of two sets */
+	private static <T> PriorityQueue<T> intersection(
+			PriorityQueue<T> set1, PriorityQueue<T> set2) {
+		PriorityQueue<T> intersection = new PriorityQueue<>(set1);
+		intersection.retainAll(set2);
+		return intersection;
+	}
+}