/// <summary>
/// Underlying implementation for Subsets() overload.
/// </summary>
/// <typeparam name="T">The type of the elements in the sequence</typeparam>
/// <param name="sequence">Sequence for which to produce subsets</param>
/// <returns>Sequence of lists representing all subsets of a sequence</returns>
private static IEnumerable <IList <T> > SubsetsImpl <T>(IEnumerable <T> sequence)
{
var sequenceAsList = sequence.ToList();
var sequenceLength = sequenceAsList.Count;
// the first subset is the empty set
yield return(new List <T>());
// all other subsets are computed using the subset generator
// this check also resolves the case of permuting empty sets
if (sequenceLength > 0)
{
for (var i = 1; i < sequenceLength; i++)
{
// each intermediate subset is a lexographically ordered K-subset
var subsetGenerator = new SubsetGenerator <T>(sequenceAsList, i);
foreach (var subset in subsetGenerator)
{
yield return(subset);
}
}
yield return(sequenceAsList); // the last subet is the original set itself
}
}
private static void Main()
{
foreach (List <int> ints in SubsetGenerator.BacktrackingGenerator(new List <int> {
1, 2, 3, 4
}, 0))
{
foreach (int i in ints)
{
Console.Write(i + " ");
}
Console.WriteLine();
}
foreach (IEnumerable <int> enumerable in SubsetGenerator.LexicalGenerator(new List <int> {
4, 3, 2, 1
}))
{
foreach (int i in enumerable)
{
Console.Write(i + " ");
}
Console.WriteLine();
}
Console.WriteLine("---------");
foreach (int[] ints in KSubsetGenerator.BacktrackingGenerator(5, 4))
{
foreach (int i in ints)
{
Console.Write(i + " ");
}
Console.WriteLine();
}
KSubsetGenerator.LexicalGenerator(5, 4);
Console.WriteLine("---------");
new PermutationGenerator().BacktrackingGeneration(new[] { 1, 2, 3, 4 }.ToArray(), 0, 3);
Console.WriteLine("---------");
//foreach (int[] subset in new PermutationGenerator().LexicalGeneration(new[] { 1, 2, 3, 4 }))
//{
// foreach (int element in subset)
// {
// Console.Write(element + " ");
// }
// Console.WriteLine();
//}
var arr = new[] { 1, 2, 3, 4 };
foreach (int i in arr)
{
Console.Write(i + " ");
}
Console.WriteLine();
while (!PermutationGenerator.NextPermutation(arr))
{
foreach (int i in arr)
{
Console.Write(i + " ");
}
Console.WriteLine();
}
}
/**
* solution:
* solution: True
* solution: True,True
* solution: True,True,True<== IsASolution
* { c a t}
* solution: True,True,False<== IsASolution
* { c a}
* solution: True,False
* solution: True,False,True<== IsASolution
* { c t}
* solution: True,False,False<== IsASolution
* { c}
* solution: False
* solution: False,True
* solution: False,True,True<== IsASolution
* { a t}
* solution: False,True,False<== IsASolution
* { a}
* solution: False,False
* solution: False,False,True<== IsASolution
* { t}
* solution: False,False,False<== IsASolution
* {} */
public static void RunTests()
{
SubsetGenerator subsetGenerator = new SubsetGenerator("cat");
subsetGenerator.GenerateSubsets();
}
