using System;

using System.Collections.Generic;

​

public class AutoCompleteHTML

{

    // Function to Auto complete the missing tag in the HTML Code

    public static (string tag, int position) autoComplete(string s)

    {

        // Split the HTML code into lines

        List<string> linesOfCode = new List<string>();

        System.Text.StringBuilder line = new System.Text.StringBuilder();

        foreach (char ch in s)

        {

            if (ch == '\n')

            {

                linesOfCode.Add(line.ToString());

                line.Clear();

            }

            else

            {

                line.Append(ch);

            }

        }

        if (line.Length > 0)

        {

            linesOfCode.Add(line.ToString());

        }

​

        // Tags which are self-closed and don't need closing

        List<string> selfClosedTags = new List<string> { "area", "base", "br", "col", "embed", "hr", "img", "input", "link", "meta", "param", "source", "track", "wbr" };

​

        Stack<string> stack = new Stack<string>();

        int count = 0;

​

        // Loop to iterate over the lines of code

        foreach (string lineCode in linesOfCode)

        {

            count++;

            for (int j = 0; j < lineCode.Length;)

            {

                // Check for end tags

                if (j + 1 < lineCode.Length && lineCode[j] == '<' && lineCode[j + 1] == '/')

                {

                    System.Text.StringBuilder tag = new System.Text.StringBuilder();

                    j += 2;

                    while (j < lineCode.Length && char.IsLower(lineCode[j]))

                    {

                        tag.Append(lineCode[j]);

                        j++;

                    }

                    while (j < lineCode.Length && lineCode[j] != '>')

                    {

                        j++;

                    }

                    if (stack.Count > 0 && !stack.Peek().Equals(tag.ToString()))

                    {

                        return ("</" + stack.Peek() + ">", count * j - 3);

                    }

                    stack.Pop();

                }

                // Skip the HTML 5 condition

                else if (j + 1 < lineCode.Length && lineCode[j] == '<' && lineCode[j + 1] == '!')

                {

                    j += 2;

                }

                // Check for start tags

                else if (lineCode[j] == '<')

                {

                    System.Text.StringBuilder tag = new System.Text.StringBuilder();

                    j++;

                    while (j < lineCode.Length && char.IsLower(lineCode[j]))

                    {

                        tag.Append(lineCode[j]);

                        j++;

                    }

                    while (j < lineCode.Length && lineCode[j] != '>')

                    {

                        j++;

                    }

                    if (!selfClosedTags.Contains(tag.ToString()))

                    {

                        stack.Push(tag.ToString());

                    }

                }

                j++;

            }

        }

​

        // Check if any tag is unbalanced then return that tag

        if (stack.Count > 0)

        {

            return ("</" + stack.Peek() + ">", s.Length);

        }

        return ("-1", 0);

    }

​

    // Driver Code

    public static void Main(string[] args)

    {

        string s = "<p><b>(TARIFFE DEDICATE – si veda htl directory) code DSV</b></p><p></p><p><b>•CAREER BAND 1-2: fino a 1.000$ a notte, tasse escluse</b></p><p><b>•CAREER BAND 3-4: fino a 700$ a notte, tasse escluse</b></p><p><b>•CAREER BAND 5-11: fino a 400$ a notte, tasse escluse</b></p><p><b>•CAREER BAND 00: nessuna restrizione, il booker avrà già effettuato il processo autorizzativo interno.&nbsp;</b></p><p><b></p><p><b></p><p></p><p></p>";

        (string tag, int position) text = (string.Empty, 0);

        while(text.tag != "-1")

        {

            text = autoComplete(s);

            Console.WriteLine(s);

            if(text.tag != "-1")

            {

                s = s.Insert(text.position, text.tag);

            }

            Console.WriteLine(text.tag + " - " + text.position);

        }

    }

}

​