solution.java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    static class DoublyLinkedListNode {
        public int data;
        public DoublyLinkedListNode next;
        public DoublyLinkedListNode prev;

        public DoublyLinkedListNode(int nodeData) {
            this.data = nodeData;
            this.next = null;
            this.prev = null;
        }
    }

    static class DoublyLinkedList {
        public DoublyLinkedListNode head;
        public DoublyLinkedListNode tail;

        public DoublyLinkedList() {
            this.head = null;
            this.tail = null;
        }

        public void insertNode(int nodeData) {
            DoublyLinkedListNode node = new DoublyLinkedListNode(nodeData);

            if (this.head == null) {
                this.head = node;
            } else {
                this.tail.next = node;
                node.prev = this.tail;
            }

            this.tail = node;
        }
    }

    public static void printDoublyLinkedList(DoublyLinkedListNode node, String sep, BufferedWriter bufferedWriter) throws IOException {
        while (node != null) {
            bufferedWriter.write(String.valueOf(node.data));

            node = node.next;

            if (node != null) {
                bufferedWriter.write(sep);
            }
        }
    }

    //Method to insert a node in a sorted doubly linked list
    static DoublyLinkedListNode sortedInsert(DoublyLinkedListNode head, int data) {
        DoublyLinkedListNode newNode = new DoublyLinkedListNode(data);
        if(head == null) {
            return newNode;
        }
        else if(head.data > newNode.data) {
            head.prev = newNode;
            newNode.next = head;
            return newNode;
        }
        /* Walk list with 2 pointers (code is cleaner than using just 1 pointer) */
        DoublyLinkedListNode n1 = null;     //to maintain previous node
        DoublyLinkedListNode n2 = head;     //to maintain current node
        while (n2 != null && n2.data < data) {
            n1 = n2;
            n2 = n2.next;
        }
        // insert at end of list
        if (n2 == null) {             
            n1.next = newNode;
            newNode.prev = n1;
        } 
        // insert somewhere within the list
        else { 
            n1.next = newNode;
            n2.prev = newNode;
            newNode.prev = n1;
            newNode.next = n2;
        }
        return head;
    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int t = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int tItr = 0; tItr < t; tItr++) {
            DoublyLinkedList llist = new DoublyLinkedList();
            int llistCount = scanner.nextInt();
            scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
            for (int i = 0; i < llistCount; i++) {
                int llistItem = scanner.nextInt();
                scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
                llist.insertNode(llistItem);
            }
            int data = scanner.nextInt();
            scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
            DoublyLinkedListNode llist1 = sortedInsert(llist.head, data);
            printDoublyLinkedList(llist1, " ", bufferedWriter);
            bufferedWriter.newLine();
        }
        bufferedWriter.close();
        scanner.close();
    }
}