217. Contains Duplicate

Added solution for 217. Contains Duplicate

Author: IshanAryendu

java/217_Contains_Duplicate.java

@@ -0,0 +1,13 @@
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        if(nums.length == 0) return false;
+        Set<Integer> set = new HashSet<>();
+        for(int num: nums){
+            if(set.contains(num)){
+                return true;
+            }
+            set.add(num);
+        }
+        return false;
+    }
+}