Create Introduction to doubly linked list

Introduction to doubly linked list

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+//Introduction to doubly linked list
+
+import java.io.*;
+import java.util.*;
+
+class Node {
+    int data;
+    Node next;
+    Node prev;
+
+    Node(int x) {
+        data = x;
+        next = null;
+        prev= null;
+    }
+}
+
+class GFG {
+    public static void main(String args[]) throws IOException {
+        Scanner sc = new Scanner(System.in);
+        int t = sc.nextInt();
+
+        while(t-- > 0) {
+            int n = sc.nextInt();
+            int[] arr =new int[n];
+
+            for(int i = 0; i < n; i++)
+                arr[i] = sc.nextInt();
+
+            Solution obj = new Solution();
+            Node ans = obj.constructDLL(arr);
+
+            while(ans != null) {
+                System.out.print(ans.data + " ");
+                ans = ans.next;
+            }
+            System.out.println();
+        }
+    }
+}
+
+class Solution {
+    Node constructDLL(int arr[]) {
+        Node head = new Node(arr[0]);
+        Node temp = head;
+
+        for(int i = 1; i < arr.length; i++) {
+            Node newNode = new Node(arr[i]);
+            newNode.next = null;
+            newNode.prev = temp;
+            temp.next = newNode;
+            temp = newNode;
+        }
+
+        return head;
+    }
+}