diff --git a/NEET150/Arrays&Hashing/leetcode217.java b/NEET150/Arrays&Hashing/leetcode217.java
new file mode 100644
index 0000000..f32ba8a
--- /dev/null
+++ b/NEET150/Arrays&Hashing/leetcode217.java
@@ -0,0 +1,28 @@
+
+import java.util.*;
+
+public class leetcode217 {
+
+    class Solution {
+
+        public boolean containsDuplicate(int[] nums) {
+            HashSet<Integer> seen = new HashSet<>(); // hashset
+            for (int num : nums) {
+                if (seen.contains(num)) {
+                    return true;
+                }
+                seen.add(num);
+            }
+            return false;
+
+        }
+    }
+}
+
+/**
+ * use hashset 
+ * iterate over a for loop 
+ * if the hashset contains the number we are trying to insert 
+ * insert that and return true
+ * or else false. 
+ */