Problem Statement 
 A set of numbers is a collection of numbers with no repeated elements. We can define the following set operations:
The UNION of two sets A and B is a set containing all the elements that are either in A or in B.
The INTERSECTION of two sets A and B is a set containing all the elements that are in both A and B.
The SYMMETRIC DIFFERENCE of two sets A and B is a set containing all the elements that are either in A or in B, but not containing elements that are in both A and B.
Given two int[]s representing sets A and B, and an operation applied on them, return a int[] representing the resulting set sorted in ascending order. If the result is an empty set then return an empty int[]. operation will be one of the following: "UNION", "INTERSECTION", "SYMMETRIC DIFFERENCE". 

Definition 
 Class:  Sets  Method:  operate  Parameters:  int[], int[], String  Returns:  int[]  Method signature:  int[] operate(int[] A, int[] B, String operation)  (be sure your method is public) 




Constraints 
  A will have between 0 and 50 elements inclusive. 
  B will have between 0 and 50 elements inclusive. 
  each element in A will be between 1000000 and 1000000 inclusive. 
  each element in B will be between 1000000 and 1000000 inclusive. 
  A will not have any repeated elements. 
  B will not have any repeated elements. 
  operation will be one of the following: "UNION", "INTERSECTION", "SYMMETRIC DIFFERENCE". 

Examples 
0)  
 {1,2,3,4}  {3,4,5,6}  "INTERSECTION" 
 Returns: { 3, 4 }  The only elements that are both in A and in B are 3 and 4. 


1)  
 {1,2,3,4}  {3,4,5,6}  "UNION" 
 Returns: { 1, 2, 3, 4, 5, 6 }  Here we return all the elements that are either in A or in B. 


2)  
 {432,756,123}  {534,76,1209}  "INTERSECTION" 
 Returns: { }  There are no common elements, so we must return an empty set. 


3)  
 {6,5,7,4}  {7,6,4,10}  "SYMMETRIC DIFFERENCE" 
 Returns: { 5, 10 }  Elements 4, 6, 7 are in both sets, thus they cannot be in our answer. However we can include elements 5 and 10. 


4)  
 {342,654,897,312,76,23,78}  {21,43,87,98,23,756,897,234,645,876,123}  "SYMMETRIC DIFFERENCE" 
 Returns: { 21, 43, 76, 78, 87, 98, 123, 234, 312, 342, 645, 654, 756, 876 }  
