/// <summary>
/// Counts the number of bits set for each output of both input comparator networks
/// if the number of set bits is different the n1 cannot be subsumed by n2 and vice versa.
/// </summary>
/// <param name="n1">The comparator network 1.</param>
/// <param name="n2">The comparator network 2.</param>
/// <returns>True if subsume test should be done, False otherwise.</returns>
private static bool ShouldCheckSubsumption(IComparatorNetwork n1, IComparatorNetwork n2)
{
#if DEBUG
if (n1.OutputsPopCount > n2.OutputsPopCount)
{
IComparatorNetwork.OutputCountBigger++;
return(false);
}
if (!SequencesAreCompatible(n1.SequencesWithOnes, n2.SequencesWithOnes))
{
IComparatorNetwork.SubsumeNoCheck1++;
return(false);
}
if (!SequencesAreCompatible(n1.Where0SetCount, n2.Where0SetCount))
{
IComparatorNetwork.SubsumeNoCheck2++;
return(false);
}
return(true);
#endif
if (n1.OutputsPopCount > n2.OutputsPopCount)
{
return(false);
}
return(SequencesAreCompatible(n1.SequencesWithOnes, n2.SequencesWithOnes) &&
SequencesAreCompatible(n1.Where0SetCount, n2.Where0SetCount));
}
private static void PrintComparatorNet(IComparatorNetwork net)
{
foreach (var c in net.Comparators)
{
Trace.Write($"({c.X},{c.Y}) ");
}
Trace.WriteLine(string.Empty);
}
/// <inheritdoc/>
public bool IsRedundant(IComparatorNetwork n)
{
//if (this.Outputs.SequenceEqual(n.Outputs))
if (this.isRedundant)
{
#if DEBUG
IComparatorNetwork.RedundantNumber++;
#endif
return(true);
}
return(false);
}
/// <inheritdoc/>
public bool IsSubsumed(IComparatorNetwork n)
{
#if DEBUG
IComparatorNetwork.SubsumeTotal++;
#endif
if (!ShouldCheckSubsumption(n, this))
{
#if DEBUG
IComparatorNetwork.SubsumeNoCheckTotal++;
#endif
return(false);
}
#if PERMUTE
// Create matrix for permutations
var positions = GetPositions(this.Where0, this.Where1, n.Where0, n.Where1);
if (positions == null)
{
return(false);
}
#if DEBUG
IComparatorNetwork.SubsumeNumber++;
#endif
#if PRUNE_GRAPH_MATCHING
var graphMatcher = new BipartiteGraphMatching();
return(graphMatcher.GetAllPerfectMatchings(positions, this.Outputs, n.Outputs, n.OutputsDual));
#endif
var permutation = new int[IComparatorNetwork.Inputs];
permutation.Populate(-1);
var succeed = TryPermutations(positions, permutation, this.Outputs, n.Outputs, this.Comparators.Length);
//var succeed = TryPermutationsIteratively(positions, positionsDual, permutation, this.Outputs, n.Outputs, n.OutputsDual, this.Comparators.Length);
#if DEBUG
if (succeed)
{
IComparatorNetwork.SubsumeSucceed++;
}
#endif
return(succeed);
#endif
return(true);
}
private static void PrintComparatorNet(IComparatorNetwork net)
{
var set = new HashSet <int>();
foreach (var c in net.Comparators)
{
var x = c.X + 1;
var y = c.Y + 1;
if (!set.Add(x) || !set.Add(y))
{
Trace.WriteLine("");
set = new HashSet <int>(new [] { x, y });
}
Trace.Write($"({x},{y}) ");
}
Trace.WriteLine(string.Empty);
}
