public override VotingSystemResult getResult(Roster roster, List <Ballot> ballotList)
{
CondorcetTally condorcetTally = new CondorcetTally(roster, ballotList);
if (Tweakables.PRINT_CONDORCET)
{
System.Console.WriteLine(condorcetTally.ToString());
}
List <List <Candidate> > candidateLoopList = findCandidateLoops(roster.candidateList, condorcetTally);
candidateLoopList = getOrderedCandidateLoopList(candidateLoopList, condorcetTally);
VotingSystemResult result = new VotingSystemResult(this);
foreach (List <Candidate> candidateLoop in candidateLoopList)
{
int score = 0;
foreach (Candidate candidate in candidateLoop)
{
score += condorcetTally.getScore(candidate);
}
score = score / candidateLoop.Count;
foreach (Candidate candidate in candidateLoop)
{
result.addCandidate(candidate, score);
}
}
if (Tweakables.PRINT_RESULTS)
{
System.Console.WriteLine(result.ToString());
}
return(result);
}
private List <Candidate> findCandidateLoop(Candidate currentCandidate, Candidate originalCandidate, List <Candidate> remainingCandidateList, List <Candidate> exploredCandidateList, CondorcetTally condorcetTally)
{
//System.Console.WriteLine("Finding loop from " + currentCandidate.ToString() + " to candidate " + originalCandidate.ToString());
List <Candidate> currentEquivelantCandidateList = new List <Candidate>();
currentEquivelantCandidateList.Add(currentCandidate);
// Any candidated tied with the current candidate is functionally the same for any loop
foreach (Candidate remainingCandidate in remainingCandidateList)
{
if (exploredCandidateList.Contains(remainingCandidate))
{
continue;
}
if (condorcetTally.getVoteDifference(currentCandidate, remainingCandidate) == 0)
{
//System.Console.WriteLine(remainingCandidate.ToString() + " is tied with our current one");
currentEquivelantCandidateList.Add(remainingCandidate);
}
}
List <Candidate> defeatedCandidateList = new List <Candidate>();
// Find all the non-explored, remaining candidates the passed canidate beats
foreach (Candidate equivelantCandidate in currentEquivelantCandidateList)
{
foreach (Candidate remainingCandidate in remainingCandidateList)
{
// If we have a candidate that has been explored or we have already beaten, continue
if (exploredCandidateList.Contains(remainingCandidate) || defeatedCandidateList.Contains(remainingCandidate))
{
continue;
}
if (condorcetTally.getVoteDifference(equivelantCandidate, remainingCandidate) > 0)
{
// See if we beat our original candidate. If so, return our equivelant candidate list
return(currentEquivelantCandidateList);
}
defeatedCandidateList.Add(remainingCandidate);
}
}
if (defeatedCandidateList.Count == 0)
{
return(null);
}
// We will look at all the found candidates, so consider them explored
exploredCandidateList.AddRange(defeatedCandidateList);
// Explore each candidate
foreach (Candidate beatenCandidate in defeatedCandidateList)
{
List <Candidate> loopList = findCandidateLoop(beatenCandidate, originalCandidate, remainingCandidateList, exploredCandidateList, condorcetTally);
if (loopList != null)
{
loopList.AddRange(currentEquivelantCandidateList);
return(loopList);
}
}
return(null);
}
private List <List <Candidate> > findCandidateLoops(List <Candidate> candidateList, CondorcetTally condorcetTally)
{
List <List <Candidate> > candidateLoopList = new List <List <Candidate> >();
List <Candidate> remainingCandidateList = candidateList.ToList();
while (remainingCandidateList.Count > 0)
{
Candidate candidate = remainingCandidateList.First();
remainingCandidateList.Remove(candidate);
List <Candidate> candidateLoop = findCandidateLoop(candidate, candidate, remainingCandidateList, new List <Candidate>(), condorcetTally);
// No loop so consider this candidate to be in his/her own loop
if (candidateLoop == null)
{
candidateLoop = new List <Candidate>();
candidateLoop.Add(candidate);
}
if (Tweakables.PRINT_CONDORCET)
{
System.Console.WriteLine("Found loop: " + Utils.ToString(candidateLoop));
}
candidateLoopList.Add(candidateLoop);
remainingCandidateList = remainingCandidateList.Except(candidateLoop).ToList();
}
return(candidateLoopList);
}
private List <Candidate> findTopCandidateLoop(List <List <Candidate> > candidateLoopList, CondorcetTally condorcetTally)
{
foreach (List <Candidate> subjectCandidateLoop in candidateLoopList)
{
Candidate subjectCandidate = subjectCandidateLoop.First();
bool subjectLoopBeaten = false;
foreach (List <Candidate> objectCandidateLoop in candidateLoopList)
{
if (subjectCandidateLoop == objectCandidateLoop)
{
continue;
}
Candidate objectCandidate = subjectCandidateLoop.First();
if (condorcetTally.getVoteDifference(subjectCandidate, objectCandidate) < 0)
{
subjectLoopBeaten = true;
break;
}
}
if (!subjectLoopBeaten)
{
return(subjectCandidateLoop);
}
}
throw new Exception("Unable to find a top Condorcet loop");
}
private List <List <Candidate> > getOrderedCandidateLoopList(List <List <Candidate> > candidateLoopList, CondorcetTally condorcetTally)
{
List <List <Candidate> > orderedCandidateLoopList = new List <List <Candidate> >();
List <List <Candidate> > remainingCandidateLoopList = candidateLoopList.ToList();
if (Tweakables.PRINT_CONDORCET)
{
System.Console.WriteLine("Ordering loops");
}
while (remainingCandidateLoopList.Count > 0)
{
List <Candidate> candidateLoop = findTopCandidateLoop(remainingCandidateLoopList, condorcetTally);
orderedCandidateLoopList.Add(candidateLoop);
remainingCandidateLoopList.Remove(candidateLoop);
if (Tweakables.PRINT_CONDORCET)
{
System.Console.WriteLine("Next loop: " + Utils.ToString(candidateLoop));
}
}
return(orderedCandidateLoopList);
}
