private static void MergeRepeatedEntries(List <WeightedState> weightedStates)
{
// Merge repeated entries for the same state
var dst = 0;
for (var i = 1; i < weightedStates.Count; ++i)
{
var srcState = weightedStates[i];
var dstState = weightedStates[dst];
if (srcState.Index == dstState.Index)
{
weightedStates[dst] =
new WeightedState(dstState.Index, dstState.Weight + srcState.Weight);
}
else
{
++dst;
if (dst != i)
{
weightedStates[dst] = srcState;
}
}
}
// truncate excess
++dst;
if (dst < weightedStates.Count)
{
weightedStates.RemoveRange(dst, weightedStates.Count - dst);
}
}
/// <summary>
/// Creates a new instance of
/// <see cref="WeightableVertexCost"/>
/// with the cost of <paramref name="startCost"/>.
/// Weighted cost is set to the same value
/// </summary>
/// <param name="startCost"></param>
public WeightableVertexCost(int startCost)
: base(startCost)
{
WeightedCost = startCost;
Status = new WeightedState();
UnweightedCostView = string.Empty;
}
/// <summary>
/// Turns weighted state set into an array. This is convenient for writing LINQ queries
/// in tests.
/// </summary>
public WeightedState[] ToArray()
{
var result = new WeightedState[this.Count];
for (var i = 0; i < this.Count; ++i)
{
result[i] = this[i];
}
return(result);
}
private static Weight NormalizeWeights(List <WeightedState> weightedStates)
{
var maxWeight = weightedStates[0].Weight;
for (var i = 1; i < weightedStates.Count; ++i)
{
if (weightedStates[i].Weight > maxWeight)
{
maxWeight = weightedStates[i].Weight;
}
}
var normalizer = Weight.Inverse(maxWeight);
for (var i = 0; i < weightedStates.Count; ++i)
{
var state = weightedStates[i];
weightedStates[i] = new WeightedState(state.Index, state.Weight * normalizer);
}
return(maxWeight);
}
public (WeightedStateSet, Weight) Get()
{
Debug.Assert(this.weightedStates.Count > 0);
var sortedStates = this.weightedStates.ToArray();
if (sortedStates.Length == 1)
{
var state = sortedStates[0];
sortedStates[0] = new WeightedState(state.Index, Weight.One);
return(new WeightedStateSet(sortedStates), state.Weight);
}
else
{
Array.Sort(sortedStates);
var maxWeight = sortedStates[0].Weight;
for (var i = 1; i < sortedStates.Length; ++i)
{
if (sortedStates[i].Weight > maxWeight)
{
maxWeight = sortedStates[i].Weight;
}
}
var normalizer = Weight.Inverse(maxWeight);
for (var i = 0; i < sortedStates.Length; ++i)
{
var state = sortedStates[i];
sortedStates[i] = new WeightedState(state.Index, state.Weight * normalizer);
}
return(new WeightedStateSet(sortedStates), maxWeight);
}
}
/// <summary>
/// Sets <see cref="WeightableVertexCost"/>
/// to weighted status. That means that
/// the current cost of vertex will be
/// set to its normal value
/// </summary>
public void MakeWeighted()
{
CurrentCost = WeightedCost;
Status = new WeightedState();
}