c# How to generate a tournament bracket HTML table

Question

so i have been stuck with this issue for 3 weeks now and i couldn\'t for the life of me figure it out. what im trying to do is to get this kind of output/presentation using tabl

Answer 1

We can implement this using System.Web.UI.WebControls.Table by dynamically adding table rows and table cells.

Class File

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

/// <summary>
/// Summary description for Matches
/// </summary>

    public class Rounds
    {
        public int RoundNumber{get;set;}
        public List<Match> Matches{get;set;}

        public Rounds(int number, List<Match> matches)
        {
            this.RoundNumber = number;
            this.Matches = matches;
        }
    }

    public class Match
    {
        public int MatchId{get;set;}
        public Team Team1{get;set;}
        public Team Team2 {get; set;}
        public Team WinningTeam { get; set; }

        public Match(int id, Team t1, Team t2) :this (id, t1, t2, null)
        {

        }

        public Match(int id, Team t1, Team t2, Team t3)
        {
            this.MatchId = id;
            this.Team1 = t1;
            this.Team2 = t2;
            this.WinningTeam = t3;
        }
    }

    public class Team
    {
        public int TeamId {get;set;}
        public string TeamName {get;set;}

        public Team(int id, string name)
        {
            this.TeamId = id;
            this.TeamName = name;
        }
    }

.aspx.cs file - We need to add a div control in .aspx file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Test : System.Web.UI.Page
{
    List<Rounds> rounds = new List<Rounds>();
    protected void Page_Load(object sender, EventArgs e)
    {
        ShowRoundMatchesUsingTable();
    }

    private List<Rounds> GetRoundMatchesDetails()
    {
        List<Team> teamList = new List<Team>();
        teamList.Add(new Team(1, "Arcenal"));
        teamList.Add(new Team(2, "Barsa"));
        teamList.Add(new Team(3, "Manchester"));
        teamList.Add(new Team(4, "Black Burn"));
        teamList.Add(new Team(5, "Ferrari"));
        teamList.Add(new Team(6, "Adidas"));
        teamList.Add(new Team(7, "Reebock"));
        teamList.Add(new Team(8, "Nike"));

        List<Match> matchList1 = new List<Match>();
        matchList1.Add(new Match(1, teamList.Find(lst => lst.TeamName == "Arcenal"), teamList.Find(lst => lst.TeamName == "Barsa")));
        matchList1.Add(new Match(1, teamList.Find(lst => lst.TeamName == "Manchester"), teamList.Find(lst => lst.TeamName == "Black Burn")));
        matchList1.Add(new Match(1, teamList.Find(lst => lst.TeamName == "Ferrari"), teamList.Find(lst => lst.TeamName == "Adidas")));
        matchList1.Add(new Match(1, teamList.Find(lst => lst.TeamName == "Reebock"), teamList.Find(lst => lst.TeamName == "Nike")));

        List<Match> matchList2 = new List<Match>();
        matchList2.Add(new Match(2, teamList.Find(lst => lst.TeamName == "Arcenal"), teamList.Find(lst => lst.TeamName == "Manchester")));
        matchList2.Add(new Match(2, teamList.Find(lst => lst.TeamName == "Adidas"), teamList.Find(lst => lst.TeamName == "Nike")));

        List<Rounds> rounds = new List<Rounds>();

        rounds.Add(new Rounds(1, matchList1));
        rounds.Add(new Rounds(2, matchList2));

        return rounds;
    }

    private void ShowRoundMatchesUsingTable()
    {
        IEnumerable<Rounds> roundsList = GetRoundMatchesDetails();

        if (roundsList == null || roundsList.Count() == 0) return;

        Table tbl = new Table();

        TableRow trHeaderRow = new TableRow();
        TableRow trDetailRow = new TableRow();
        TableCell tcDetails = new TableCell();

        foreach (Rounds round in roundsList)
        {
            TableHeaderCell th = new TableHeaderCell();
            th.Text = "Round : " + round.RoundNumber ;
            trHeaderRow.Cells.Add(th);

            if (round.Matches != null && round.Matches.Count > 0)
            {
                tcDetails = new TableCell();
                trDetailRow.Cells.Add(tcDetails);
            }

            foreach (Match m in round.Matches)
            {
                Table dtlTable = new Table();
                tcDetails.Controls.Add(dtlTable);

                TableRow tr1 = new TableRow();
                TableCell tc = new TableCell();
                tc.Text = m.Team1.TeamName;
                tr1.Cells.Add(tc);
                dtlTable.Rows.Add(tr1);

                tr1 = new TableRow();
                tc = new TableCell();
                tc.Text = "Vs";
                tr1.Cells.Add(tc);
                dtlTable.Rows.Add(tr1);

                tr1 = new TableRow();
                tc = new TableCell();
                tc.Text = m.Team2.TeamName;
                tr1.Cells.Add(tc);
                dtlTable.Rows.Add(tr1);
            }
        }

        tbl.Rows.Add(trHeaderRow);
        tbl.Rows.Add(trDetailRow);
        div.Controls.Add(tbl);
    }
}

Answer 2

Here's my attempt. I have tested the code for 2, 3, and 4 Round Tournaments. The outputs for a 2-Round and 3-Round tournament are shown here:

---

---

I have used the same model that you provided to define a Match. I have added a Tournament class to generate test data.

Match.cs - The class containing the models

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace tournament
{
    public class Match
    {
        public int id { get; set; }
        public int teamid1 { get; set; }
        public int teamid2 { get; set; }
        public int roundnumber { get; set; }
        public int winner { get; set; }

        public Match(int id, int teamid1, int teamid2, int roundnumber, int winner)
        {
            this.id = id;
            this.teamid1 = teamid1;
            this.teamid2 = teamid2;
            this.roundnumber = roundnumber;
            this.winner = winner;
        }
    }

    public class Tournament
    {
        public SortedList<int, SortedList<int, Match>> TournamentRoundMatches { get; private set; }
        public Match ThirdPlaceMatch { get; private set; }

        public Tournament(int rounds)
        {
            this.TournamentRoundMatches = new SortedList<int, SortedList<int, Match>>();
            this.GenerateTournamentResults(rounds);
            if (rounds > 1)
            {
                this.GenerateThirdPlaceResult(rounds);
            }
        }

        public void AddMatch(Match m)
        {
            if (this.TournamentRoundMatches.ContainsKey(m.roundnumber))
            {
                if (!this.TournamentRoundMatches[m.roundnumber].ContainsKey(m.id))
                {
                    this.TournamentRoundMatches[m.roundnumber].Add(m.id, m);
                }
            }
            else
            {
                this.TournamentRoundMatches.Add(m.roundnumber, new SortedList<int, Match>());
                this.TournamentRoundMatches[m.roundnumber].Add(m.id, m);
            }
        }

        private void GenerateTournamentResults(int rounds)
        {
            Random WinnerRandomizer = new Random();

            for (int round = 1, match_id = 1; round <= rounds; round++)
            {
                int matches_in_round = 1 << (rounds - round);
                for (int round_match = 1; round_match <= matches_in_round; round_match++, match_id++)
                {
                    int team1_id;
                    int team2_id;
                    int winner;
                    if (round == 1)
                    {
                        team1_id = (match_id * 2) - 1;
                        team2_id = (match_id * 2);
                    }
                    else
                    {
                        int match1 = (match_id - (matches_in_round * 2) + (round_match - 1));
                        int match2 = match1 + 1;
                        team1_id = this.TournamentRoundMatches[round - 1][match1].winner;
                        team2_id = this.TournamentRoundMatches[round - 1][match2].winner;
                    }
                    winner = (WinnerRandomizer.Next(1, 3) == 1) ? team1_id : team2_id;
                    this.AddMatch(new Match(match_id, team1_id, team2_id, round, winner));
                }
            }
        }

        private void GenerateThirdPlaceResult(int rounds)
        {
            Random WinnerRandomizer = new Random();
            int semifinal_matchid1 = this.TournamentRoundMatches[rounds - 1].Keys.ElementAt(0);
            int semifinal_matchid2 = this.TournamentRoundMatches[rounds - 1].Keys.ElementAt(1);
            Match semifinal_1 = this.TournamentRoundMatches[rounds - 1][semifinal_matchid1];
            Match semifinal_2 = this.TournamentRoundMatches[rounds - 1][semifinal_matchid2];
            int semifinal_loser1 = (semifinal_1.winner == semifinal_1.teamid1) ? semifinal_1.teamid2 : semifinal_1.teamid1;
            int semifinal_loser2 = (semifinal_2.winner == semifinal_2.teamid1) ? semifinal_2.teamid2 : semifinal_2.teamid1;
            int third_place_winner = (WinnerRandomizer.Next(1, 3) == 1) ? semifinal_loser1 : semifinal_loser2;
            this.ThirdPlaceMatch = new Match((1 << rounds) + 1, semifinal_loser1, semifinal_loser2, 1, third_place_winner);
        }
    }
}

---

I have generated the raw HTML dynamically using the static method GenerateHTMLResultsTable. This was done using only <table> without any need for <div> blocks.

Program.cs - The static Program class that initializes test data and generates the HTML

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace tournament
{
    class Program
    {
        static string GenerateHTMLResultsTable(Tournament tournament)
        {
            int match_white_span;
            int match_span;
            int position_in_match_span;
            int column_stagger_offset;
            int effective_row;
            int col_match_num;
            int cumulative_matches;
            int effective_match_id;
            int rounds = tournament.TournamentRoundMatches.Count;
            int teams = 1 << rounds;
            int max_rows = teams << 1;
            StringBuilder HTMLTable = new StringBuilder();

            HTMLTable.AppendLine("<style type=\"text/css\">");
            HTMLTable.AppendLine("    .thd {background: rgb(220,220,220); font: bold 10pt Arial; text-align: center;}");
            HTMLTable.AppendLine("    .team {color: white; background: rgb(100,100,100); font: bold 10pt Arial; border-right: solid 2px black;}");
            HTMLTable.AppendLine("    .winner {color: white; background: rgb(60,60,60); font: bold 10pt Arial;}");
            HTMLTable.AppendLine("    .vs {font: bold 7pt Arial; border-right: solid 2px black;}");
            HTMLTable.AppendLine("    td, th {padding: 3px 15px; border-right: dotted 2px rgb(200,200,200); text-align: right;}");
            HTMLTable.AppendLine("    h1 {font: bold 14pt Arial; margin-top: 24pt;}");
            HTMLTable.AppendLine("</style>");

            HTMLTable.AppendLine("<h1>Tournament Results</h1>");
            HTMLTable.AppendLine("<table border=\"0\" cellspacing=\"0\">");
            for (int row = 0; row <= max_rows; row++)
            {
                cumulative_matches = 0;
                HTMLTable.AppendLine("    <tr>");
                for (int col = 1; col <= rounds + 1; col++)
                {
                    match_span = 1 << (col + 1);
                    match_white_span = (1 << col) - 1;
                    column_stagger_offset = match_white_span >> 1;
                    if (row == 0)
                    {
                        if (col <= rounds)
                        {
                            HTMLTable.AppendLine("        <th class=\"thd\">Round " + col + "</th>");
                        }
                        else
                        {
                            HTMLTable.AppendLine("        <th class=\"thd\">Winner</th>");
                        }
                    }
                    else if (row == 1)
                    {
                        HTMLTable.AppendLine("        <td class=\"white_span\" rowspan=\"" + (match_white_span - column_stagger_offset) + "\">&nbsp;</td>");
                    }
                    else
                    {
                        effective_row = row + column_stagger_offset;
                        if (col <= rounds)
                        {
                            position_in_match_span = effective_row % match_span;
                            position_in_match_span = (position_in_match_span == 0) ? match_span : position_in_match_span;
                            col_match_num = (effective_row / match_span) + ((position_in_match_span < match_span) ? 1 : 0);
                            effective_match_id = cumulative_matches + col_match_num;
                            if ((position_in_match_span == 1) && (effective_row % match_span == position_in_match_span))
                            {
                                HTMLTable.AppendLine("        <td class=\"white_span\" rowspan=\"" + match_white_span + "\">&nbsp;</td>");
                            }
                            else if ((position_in_match_span == (match_span >> 1)) && (effective_row % match_span == position_in_match_span))
                            {
                                HTMLTable.AppendLine("        <td class=\"team\">Team " + tournament.TournamentRoundMatches[col][effective_match_id].teamid1 + "</td>");
                            }
                            else if ((position_in_match_span == ((match_span >> 1) + 1)) && (effective_row % match_span == position_in_match_span))
                            {
                                HTMLTable.AppendLine("        <td class=\"vs\" rowspan=\"" + match_white_span + "\">VS</td>");
                            }
                            else if ((position_in_match_span == match_span) && (effective_row % match_span == 0))
                            {
                                HTMLTable.AppendLine("        <td class=\"team\">Team " + tournament.TournamentRoundMatches[col][effective_match_id].teamid2 + "</td>");
                            }
                        }
                        else
                        {
                            if (row == column_stagger_offset + 2)
                            {
                                HTMLTable.AppendLine("        <td class=\"winner\">Team " + tournament.TournamentRoundMatches[rounds][cumulative_matches].winner + "</td>");
                            }
                            else if (row == column_stagger_offset + 3)
                            {
                                HTMLTable.AppendLine("        <td class=\"white_span\" rowspan=\"" + (match_white_span - column_stagger_offset) + "\">&nbsp;</td>");
                            }
                        }
                    }
                    if (col <= rounds)
                    {
                        cumulative_matches += tournament.TournamentRoundMatches[col].Count;
                    }
                }
                HTMLTable.AppendLine("    </tr>");
            }
            HTMLTable.AppendLine("</table>");

            HTMLTable.AppendLine("<h1>Third Place Results</h1>");
            HTMLTable.AppendLine("<table border=\"0\" cellspacing=\"0\">");
            HTMLTable.AppendLine("    <tr>");
            HTMLTable.AppendLine("        <th class=\"thd\">Round 1</th>");
            HTMLTable.AppendLine("        <th class=\"thd\">Third Place</th>");
            HTMLTable.AppendLine("    </tr>");
            HTMLTable.AppendLine("    <tr>");
            HTMLTable.AppendLine("        <td class=\"white_span\">&nbsp;</td>");
            HTMLTable.AppendLine("        <td class=\"white_span\" rowspan=\"2\">&nbsp;</td>");
            HTMLTable.AppendLine("    </tr>");
            HTMLTable.AppendLine("    <tr>");
            HTMLTable.AppendLine("        <td class=\"team\">Team " + tournament.ThirdPlaceMatch.teamid1 + "</td>");
            HTMLTable.AppendLine("    </tr>");
            HTMLTable.AppendLine("    <tr>");
            HTMLTable.AppendLine("        <td class=\"vs\">VS</td>");
            HTMLTable.AppendLine("        <td class=\"winner\">Team " + tournament.ThirdPlaceMatch.winner + "</td>");
            HTMLTable.AppendLine("    </tr>");
            HTMLTable.AppendLine("    <tr>");
            HTMLTable.AppendLine("        <td class=\"team\">Team " + tournament.ThirdPlaceMatch.teamid2 + "</td>");
            HTMLTable.AppendLine("        <td class=\"white_span\">&nbsp;</td>");
            HTMLTable.AppendLine("    </tr>");
            HTMLTable.AppendLine("</table>");
            return HTMLTable.ToString();
        }

        static void Main(string[] args)
        {
            Tournament Test3RoundTournament = new Tournament(3);
            Tournament Test2RoundTournament = new Tournament(2);
            File.WriteAllText(@"C:\Tournament\results.html", GenerateHTMLResultsTable(Test2RoundTournament));
            File.WriteAllText(@"C:\Tournament\results.html", GenerateHTMLResultsTable(Test3RoundTournament));
            Console.ReadLine();
        }
    }
}

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UPDATE

Explanation of Parameters Used to Generate the HTML Table

As you can see, the column_stagger_offset is the amount by which each column is shifted up to align them the way they are supposed to. The effective_row is essentially where the particular table cell would have been had there been no vertical shift. Knowing the effective_row and the position_in_match_span helps determine what needs to be shown in that particuar cell (blank, team1, team2, or vs.).

As you've noticed, I am iterating over the columns one row at a time. That seems most natural considering that HTML tables are also constructed that way, i.e. create row, add cells ... create row, add cels ... and so on.