add 2215

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 | #    |      Title     | Solutions                                                                                                                                | Video                                                                         | Difficulty  | Tag                  
 |------|----------------|------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|-------------|-------------
+| 2215 |[Find the Difference of Two Arrays](https://leetcode.com/problems/find-the-difference-of-two-arrays/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2215.java)                                                                     || Easy                                                                          ||
 | 2210 |[Count Hills and Valleys in an Array](https://leetcode.com/problems/count-hills-and-valleys-in-an-array/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2210.java)                                                                     || Easy                                                                          ||
 | 2208 |[Minimum Operations to Halve Array Sum](https://leetcode.com/problems/minimum-operations-to-halve-array-sum/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2208.java)                                                                     || Medium                                                                          ||
 | 2206 |[Divide Array Into Equal Pairs](https://leetcode.com/problems/divide-array-into-equal-pairs/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2206.java)                                                                     || Easy                                                                          ||

src/main/java/com/fishercoder/solutions/_2215.java

@@ -0,0 +1,23 @@
+package com.fishercoder.solutions;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class _2215 {
+    public static class Solution1 {
+        public List<List<Integer>> findDifference(int[] nums1, int[] nums2) {
+            Set<Integer> set1 = Arrays.stream(nums1).boxed().collect(Collectors.toSet());
+            Set<Integer> set1Copy = new HashSet<>(set1);
+            Set<Integer> set2 = Arrays.stream(nums2).boxed().collect(Collectors.toSet());
+            set1.removeAll(set2);
+            set2.removeAll(set1Copy);
+            List<Integer> list1 = set1.stream().mapToInt(n -> n).boxed().collect(Collectors.toList());
+            List<Integer> list2 = set2.stream().mapToInt(n -> n).boxed().collect(Collectors.toList());
+            return new ArrayList<>(Arrays.asList(list1, list2));
+        }
+    }
+}