Create pashmeen Q9 solution

Q9/pashmeen Q9 solution

@@ -0,0 +1,30 @@
+// "static void main" must be defined in a public class.
+import java.util.Scanner;
+import java.util.HashMap;
+
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner s=new Scanner(System.in);
+        int n=s.nextInt();
+        int arr[]=new int[n];
+        for(int i=0;i<n;i++)
+            arr[i]=s.nextInt();
+        findDuplicate(arr,n);
+    }
+    public static void findDuplicate(int[] arr, int n)
+    {
+        HashMap<Integer,Integer> hm=new HashMap<Integer,Integer>();
+        for(int i=0;i<n;i++)
+        {
+            if(!hm.containsKey(arr[i]))
+                hm.put(arr[i],1);
+            else if(hm.containsKey(arr[i]))
+            {
+                System.out.println(arr[i]);
+                return;
+            }
+        }
+        System.out.println("-1");
+    }
+}