/// <summary>
/// Attempts to create a new round of (legal) Swiss matchups.
/// This takes all prior results into account for the following:
/// - Match strong players together, and weak players together.
/// - No rematches.
/// - No repeat byes.
/// If a new legal round is created, the next Bracket round is populated.
/// </summary>
/// <param name="_gamesPerMatch">Max Games for each Match</param>
/// <returns>true on success, false on failure</returns>
private bool AddSwissRound(int _gamesPerMatch)
{
// Don't try to populate nonexistent rounds:
if (ActiveRound >= NumberOfRounds)
{
return(false);
}
#region Swiss Algorithm
// CreateGroups() divides players into "groups"
// based on their W/L record.
List <List <int> > scoreBrackets = CreateGroups();
// GetHeuristicEdges() generates a graph representing
// matchup preferences between every player.
// Players with the same record and no prior matchups
// will have a very low heuristic value here.
List <int[]> possibleMatches = GetHeuristicEdges(scoreBrackets);
// Access the Python weight-matching script:
var engine = IronPython.Hosting.Python.CreateEngine();
var scope = engine.CreateScope();
engine.ExecuteFile("mwmatching.py", scope);
dynamic maxWeightMatching = scope.GetVariable("maxWeightMatching");
// Calling maxWeightMatching returns a Swiss matchup solution (if possible).
// The resulting list is a list of legal matchups:
IronPython.Runtime.List pySolution = maxWeightMatching(possibleMatches, true);
#endregion
#region Legal Checks
// Double-check that all the new matchups are Swiss-legal.
// Create a list of all the new Matchups:
List <Matchup> newRoundMatchups = new List <Matchup>();
for (int i = 0; i < pySolution.Count; ++i)
{
// 'i' = 'Defender index'
// 'pySolution[i]' = 'Challenger index'
int challengerIndex = Convert.ToInt32(pySolution[i]);
if (i == challengerIndex)
{
// Player is matched against himself!
return(false);
}
else if (i > challengerIndex)
{
continue;
}
Matchup newMatchup = new Matchup(i, challengerIndex, (1 + ActiveRound));
foreach (Matchup m in Matchups)
{
if (m.HasMatchingPlayers(newMatchup))
{
// This is a rematch from a previous round!
return(false);
}
}
foreach (Matchup m in newRoundMatchups)
{
if (m.ContainsInt(newMatchup.DefenderIndex) ||
m.ContainsInt(newMatchup.ChallengerIndex))
{
// A player has multiple matchups this round!
return(false);
}
}
newRoundMatchups.Add(newMatchup);
}
if (newRoundMatchups.Count < (int)(Players.Count * 0.5))
{
// Not enough Matchups were created!
// (probably means: unable to create enough legal matches)
return(false);
}
#endregion
#region New Round Populating
// CONFIRMED LEGAL!
// Populate the next round of Matches with these Players:
for (int i = 0; i < newRoundMatchups.Count; ++i)
{
int matchNum = (i + 1 + (newRoundMatchups.Count * ActiveRound));
Matches[matchNum].AddPlayer(Players[newRoundMatchups[i].DefenderIndex]);
Matches[matchNum].AddPlayer(Players[newRoundMatchups[i].ChallengerIndex]);
}
++ActiveRound;
// Add the new Matchups to our matchups list:
Matchups.AddRange(newRoundMatchups);
// Now that we have a new legal round...
// Award points to the player with a bye, if there is one:
if (PlayerByes.Count > 0)
{
int rIndex = Rankings.FindIndex(r => r.Id == PlayerByes[PlayerByes.Count - 1]);
Rankings[rIndex].AddMatchOutcome(Outcome.Win, true);
UpdateRankings();
}
#endregion
return(true);
}