Compare Two Linked List

Comparing Hacker Rank 

Code Snippet for CompareLists

static bool CompareLists(SinglyLinkedListNode head1, SinglyLinkedListNode head2) 
    {
        var flag = false;
        while(true)
        {
            if(head1!=null)
            {
                if(head2!=null)
                {
                    if(head2.data==head1.data)
                    {
                        flag = true;
                        head2=head2.next;
                        head1=head1.next;
                    }
                    else
                        return false;
                }
                else
                    return false;
                
            }
            else if(head2!=null)
               return false;
            else
                return true;
        }
        return flag;
    }

Full Code Snippet

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    class SinglyLinkedListNode {
        public int data;
        public SinglyLinkedListNode next;

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

    class SinglyLinkedList {
        public SinglyLinkedListNode head;
        public SinglyLinkedListNode tail;

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

        public void InsertNode(int nodeData) {
            SinglyLinkedListNode node = new SinglyLinkedListNode(nodeData);

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

            this.tail = node;
        }
    }

    static void PrintSinglyLinkedList(SinglyLinkedListNode node, string sep, TextWriter textWriter) {
        while (node != null) {
            textWriter.Write(node.data);

            node = node.next;

            if (node != null) {
                textWriter.Write(sep);
            }
        }
    }

    // Complete the CompareLists function below.

    /*
     * For your reference:
     *
     * SinglyLinkedListNode {
     *     int data;
     *     SinglyLinkedListNode next;
     * }
     *
     */
    static bool CompareLists(SinglyLinkedListNode head1, SinglyLinkedListNode head2) 
    {
        var flag = false;
        while(true)
        {
            if(head1!=null)
            {
                if(head2!=null)
                {
                    if(head2.data==head1.data)
                    {
                        flag = true;
                        head2=head2.next;
                        head1=head1.next;
                    }
                    else
                        return false;
                }
                else
                    return false;
                
            }
            else if(head2!=null)
               return false;
            else
                return true;
        }
        return flag;
    }

    static void Main(string[] args) {
        TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

        int tests = Convert.ToInt32(Console.ReadLine());

        for (int testsItr = 0; testsItr < tests; testsItr++) {
            SinglyLinkedList llist1 = new SinglyLinkedList();

            int llist1Count = Convert.ToInt32(Console.ReadLine());

            for (int i = 0; i < llist1Count; i++) {
                int llist1Item = Convert.ToInt32(Console.ReadLine());
                llist1.InsertNode(llist1Item);
            }
          
          	SinglyLinkedList llist2 = new SinglyLinkedList();

            int llist2Count = Convert.ToInt32(Console.ReadLine());

            for (int i = 0; i < llist2Count; i++) {
                int llist2Item = Convert.ToInt32(Console.ReadLine());
                llist2.InsertNode(llist2Item);
            }

            bool result = CompareLists(llist1.head, llist2.head);

            textWriter.WriteLine((result ? 1 : 0));
        }

        textWriter.Flush();
        textWriter.Close();
    }
}