// old search method
/*
* private void search2(IBestChoiceSearcher bestChoiceSearcher, PropagationResult result, List<Solution> solutions)
* {
* Set[,] s = result.matrix;
*
* // Find the top list of possible choices of Set with maximum minFactor range.
* List<FactorRangeRecord> bestRecords = searchForTheBestRecords(s);
* // If the it is only one possible Set, after shorten will be matrix singleton
* bool isSingleton = bestRecords.Count == 1;
*
* // Find the set to be shortened.
* FactorRangeRecord best = bestChoiceSearcher.chooseBestRecord(bestRecords);
* Set currentSet = s[best.Row, best.Col];
*
* // Create the order in which we will try to find a solution, best possibility first.
* List<int> sortedMinutes = new List<int>(currentSet.MinimizationFactor.Keys);
* sortedMinutes.Sort(delegate(int i, int j)
* {
* return currentSet.MinimizationFactor[i] - currentSet.MinimizationFactor[j];
* });
*
* // Search for the solution.
* foreach (int minute in sortedMinutes)
* {
* // TODO: Use the branch and bound prunning.
*
* // Copy the matrix.
* Set[,] newMatrix = GenerationAlgorithmPESPUtil.cloneDiscreteSetMatrix(s);
*
* // Create a singleton set.
* Set newSet = new Set(currentSet.Modulo);
* newSet.Add(minute, currentSet.MinimizationFactor[minute]);
*
* // Remeber to the new matrix.
* newMatrix[best.Row, best.Col] = newSet;
* newMatrix[best.Col, best.Row] = new Set(newSet);
* newMatrix[best.Col, best.Row].Reverse();
*
* // Propagate newly created constraints.
* PropagationUtils.propagate(newMatrix, result.TrainLinesMap);
*
* // Check if the solution may be found.
* if (!MatrixUtils.isValid(s))
* {
* continue;
* }
*
* // If the solution is found, remember it, otherwise search for it.
* if (isSingleton)
* {
* solutions.Add(new Solution(newMatrix));
* }
* else
* {
* search(new PropagationResult(newMatrix, result.TrainLinesMap), solutions);
* }
* }
* }
*/
/// <summary>
/// Searches for solution.
/// It is called recursively, backtracking all possiblities with respect to specific choice searcher.
/// </summary>
/// <param name="bestChoiceSearcher">The best choice searcher.</param>
/// <param name="propagationResult">The propagation result.</param>
/// <param name="solutions">The solutions.</param>
/// <returns>True if solution found, terminate recursive calls. Otherwise continue in backtracking.</returns>
private Boolean search(IBestChoiceSearcher bestChoiceSearcher, PropagationResult propagationResult, List <Solution> solutions)
{
//reportProgress();
// retreive discrete set matrix after propagation from propagation result
Set[,] discreteSetMatrix = propagationResult.DiscreteSetMatrix;
// while until you can still find some solution (still can found best record)
while (true)
{
// Propagate newly created constraints.
PropagationUtil.propagate(discreteSetMatrix, propagationResult.TrainLinesMap);
// Check if the solution may be found.
if (!MatrixUtils.isValid(discreteSetMatrix))
{
// No valid matrix - solution can not be found.
return(false);
}
// Find the set to be shortened.
FactorRangeRecord bestRecord;
// if no best record found ()
if (!bestChoiceSearcher.chooseBestRecord(discreteSetMatrix, out bestRecord))
{
// then solution found, matrix is single (contains singletons only).
solutions.Add(new Solution(discreteSetMatrix));
// End of recursive calls
return(true);
}
reportProgress();
// fix one potential set with item founded as best
Set[,] newMatrix = fixOnePotentialOfSetInMatrix(discreteSetMatrix, bestRecord);
// matrix was changed, continue in recursive calls
Boolean solutionFound = search(bestChoiceSearcher, new PropagationResult(newMatrix, propagationResult.TrainLinesMap), solutions);
// Test if solution was found
if (solutionFound)
{
return(true);
}
// after return from recursive call, remove fixed object and try to
discreteSetMatrix[bestRecord.Row, bestRecord.Col].Remove(bestRecord.MinItemOfSet);
discreteSetMatrix[bestRecord.Col, bestRecord.Row].RemoveReverse(bestRecord.MinItemOfSet);
}
}
/// <summary>
/// Runs the bisection algorithm for initial phase of constraint propagation.
/// </summary>
/// <param name="constraints">List of constraints.</param>
/// <param name="constraintSetsCreator">Creator of the sets of constraints.</param>
/// <param name="lowerBoundStart">Lower bound for the bisection search.</param>
/// <param name="upperBoundStart">Upper bound for the bisection search.</param>
/// <returns>Result of the initial algorithm phase.</returns>
public static PropagationResult Bisect(List <Constraint> constraints, IConstraintSetsCreator constraintSetsCreator, int lowerBoundStart, int upperBoundStart)
{
// create the result.
PropagationResult result = new PropagationResult();
//-------bisection-algorithm-for-finding-the-proper-bound-for-discret-set------
// set default lower and upper bounds
int lowerBound = lowerBoundStart;
int upperBound = upperBoundStart;
// set the boolean loop variable
Boolean loop = true;
int midpoint = 0;
// loop while bounds are not crossed and loop
while ((upperBound - lowerBound) > 1 && loop)
{
midpoint = (upperBound + lowerBound) / 2;
// run rpopagation algorithm, which create constraintSet, constraintMatrix
// and propagate it (make it stable)
result = PropagationUtil.runPropagationAlgorithm(constraints, constraintSetsCreator, midpoint);
// if the constraint matrix is stable (previously), and valid
if (MatrixUtils.isValid(result.DiscreteSetMatrix))
{
// change upperbound of interval, right part is thrown away
upperBound = midpoint;
}
else
{
// change lowerbound of interval, left part is thrown away
lowerBound = midpoint;
}
}
// if the current found value is not valid, move to the looser restrictions
while (!MatrixUtils.isValid(result.DiscreteSetMatrix) && midpoint <= upperBoundStart)
{
result = PropagationUtil.runPropagationAlgorithm(constraints, constraintSetsCreator, ++midpoint);
}
// return the found result.
return(result);
}
