static void BeGreedy(this IGraph_uint graph, uint[] colorGraph, ref uint liveVertexBits, int c)
{
while (true)
{
var originalBits = liveVertexBits;
var bits = liveVertexBits;
while (bits != 0)
{
var bit = bits & (~bits + 1);
bits ^= bit;
var colorCount = 0;
for (int i = c; i < colorGraph.Length; i++)
{
if ((bit & colorGraph[i]) != 0)
{
colorCount++;
}
}
if (colorCount > graph.DegreeInSet(bit.Extract(), liveVertexBits))
{
liveVertexBits ^= bit;
}
}
if (liveVertexBits == originalBits)
{
break;
}
}
}
public static bool IsChoosable(this IGraph_uint graph, uint[] colorGraph, out long nodesVisited, out long cacheHits)
{
nodesVisited = 0;
cacheHits = 0;
//var cache = new Dictionary<BitLevelGeneration.HashedAssignment_uint, bool>();
Dictionary <BitLevelGeneration.HashedAssignment_uint, bool> cache = null;
return(graph.IsChoosable(colorGraph, Enumerable.Range(0, graph.N).To_uint(), 0, cache, ref nodesVisited, ref cacheHits));
}
static bool IsChoosable(this IGraph_uint graph, uint[] colorGraph, uint liveVertexBits, int c, Dictionary <BitLevelGeneration.HashedAssignment_uint, bool> cache, ref long nodesVisited, ref long cacheHits)
{
nodesVisited++;
graph.BeGreedy(colorGraph, ref liveVertexBits, c);
if (liveVertexBits == 0)
{
return(true);
}
if ((liveVertexBits & ~colorGraph.Or(c)) != 0)
{
return(false);
}
//bool cachedResult;
//var key = new BitLevelGeneration.HashedAssignment_uint(colorGraph, c, liveVertexBits);
//if (cache.TryGetValue(key, out cachedResult))
//{
// cacheHits++;
// return cachedResult;
//}
var choosable = false;
var V = colorGraph[c] & liveVertexBits;
foreach (var C in graph.MaximalIndependentSubsets(V))
{
if (graph.IsChoosable(colorGraph, liveVertexBits ^ C, c + 1, cache, ref nodesVisited, ref cacheHits))
{
choosable = true;
break;
}
}
//cache[key] = choosable;
return(choosable);
}
public static bool IsChoosable(this IGraph_uint graph, uint[] colorGraph)
{
long nodesVisited, cacheHits;
return(graph.IsChoosable(colorGraph, out nodesVisited, out cacheHits));
}
public static bool IsFChoosable(this IGraph_uint graph, Func <int, int> f, out List <List <int> > badAssignment, out long nodesVisited, out long cacheHits)
{
badAssignment = null;
nodesVisited = 0;
cacheHits = 0;
var liveVertexBits = Enumerable.Range(0, graph.N).To_uint();
var sizes = graph.Vertices.Select(v => f(v)).ToList();
var maxListSize = sizes.Max();
for (int potSize = maxListSize; potSize < graph.N; potSize++)
{
//var cache = new Dictionary<BitLevelGeneration.HashedAssignment_uint, bool>();
Dictionary <BitLevelGeneration.HashedAssignment_uint, bool> cache = null;
foreach (var colorGraph in BitLevelGeneration.Assignments_uint.Enumerate(sizes, potSize))
{
if (potSize > maxListSize)
{
uint xx = 0;
for (int i = 0; i < colorGraph.Length; i++)
{
xx |= colorGraph[i];
if (xx.PopulationCount() <= i + 1)
{
goto skip;
}
}
for (int i = 0; i < colorGraph.Length; i++)
{
for (int j = i + 1; j < colorGraph.Length; j++)
{
if ((colorGraph[i] & colorGraph[j]) == 0)
{
goto skip;
}
}
}
foreach (var color in colorGraph)
{
if (graph.IsIndependent(color))
{
goto skip;
}
}
}
if (!graph.IsChoosable(colorGraph, liveVertexBits, 0, cache, ref nodesVisited, ref cacheHits))
{
badAssignment = new List <List <int> >();
foreach (var v in graph.Vertices)
{
var list = new List <int>();
uint bit = 1U << v;
for (int i = 0; i < colorGraph.Length; i++)
{
if ((bit & colorGraph[i]) != 0)
{
list.Add(i);
}
}
badAssignment.Add(list);
}
return(false);
}
skip :;
}
}
return(true);
}
public static bool IsFChoosable(this IGraph_uint graph, Func <int, int> f, out List <List <int> > badAssignment)
{
long nodesVisited, cacheHits;
return(graph.IsFChoosable(f, out badAssignment, out nodesVisited, out cacheHits));
}