private ElementType GetMinimumSum(
IntegerSequence chosenReferences,
SparseDictionaryMathMatrix <ElementType> currentMatrix,
ElementType[] currentLineBoard,
IEnumerable <KeyValuePair <int, ILongSparseMatrixLine <ElementType> > > lines,
int chosenSolution)
{
var sum = this.ring.AdditiveUnity;
var solutionValue = chosenReferences[chosenSolution];
var minimumCover = GetMinimumCover(chosenReferences, lines, solutionValue);
sum = this.ring.Add(sum, minimumCover);
var columns = currentMatrix.GetColumns(solutionValue);
foreach (var column in columns)
{
if (column.Key != solutionValue)
{
var currentValue = currentMatrix[solutionValue, column.Key];
if (this.ring.Equals(currentValue, currentLineBoard[column.Key]))
{
minimumCover = this.GetMinimumCover(
chosenReferences,
lines,
column.Key);
minimumCover = this.ring.Add(minimumCover, this.ring.AdditiveInverse(currentValue));
sum = this.ring.Add(sum, minimumCover);
}
}
}
return(sum);
}
/// <summary>
/// Escolhe a referência que minimiza a perda.
/// </summary>
/// <param name="chosenReferences">As referências escolhidas anteriormente.</param>
/// <param name="currentMatrix">A matriz dos custos.</param>
/// <param name="currentLineBoard">A linha que contém a condensação dos custos das linhas escolhidas.</param>
/// <returns>O índice da linha correspondente à próxima referência bem como a perda respectiva.</returns>
public Tuple <int, ElementType> Run(
IntegerSequence chosenReferences,
SparseDictionaryMathMatrix <ElementType> currentMatrix,
ElementType[] currentLineBoard)
{
var result = -1;
var currentMinimumLost = default(ElementType);
var lines = currentMatrix.GetLines();
if (chosenReferences.Count > 2)
{
currentMinimumLost = this.GetMinimumSum(
chosenReferences,
currentMatrix,
currentLineBoard,
lines,
2);
result = 2;
}
Parallel.For(2, chosenReferences.Count,
chosenSolution =>
{
var sum = this.GetMinimumSum(
chosenReferences,
currentMatrix,
currentLineBoard,
lines,
chosenSolution);
lock (this.lockObject)
{
if (this.comparer.Compare(sum, currentMinimumLost) < 0)
{
currentMinimumLost = sum;
result = chosenSolution;
}
}
});
if (result != -1)
{
var solutionValue = chosenReferences[result];
var minimumCover = this.GetMinimumCover(
chosenReferences,
lines,
solutionValue);
currentLineBoard[solutionValue] = minimumCover;
var columns = currentMatrix.GetColumns(solutionValue);
foreach (var column in columns)
{
if (column.Key != solutionValue)
{
var currentValue = currentMatrix[solutionValue, column.Key];
if (this.ring.Equals(currentValue, currentLineBoard[column.Key]))
{
minimumCover = this.GetMinimumCover(
chosenReferences,
lines,
solutionValue);
currentLineBoard[column.Key] = minimumCover;
}
}
}
}
return(Tuple.Create(result, currentMinimumLost));
}
