private static List <List <int> > GetPossibleSetsFromIndices2(List <int> list)
{
var results = new List <List <int> >();
for (int t1 = 0; t1 < list.Count; t1++)
{
for (int t2 = t1; t2 < list.Count; t2++)
{
if (t2 == t1)
{
continue;
}
for (int t3 = t2; t3 < list.Count; t3++)
{
if (t3 == t2 || t3 == t1)
{
continue;
}
var result = new List <int> {
list[t1], list[t2], list[t3]
};
if (U.is_chi(result) || U.is_pon(result))
{
results.Add(result);
}
}
}
}
return(results);
}
// Replaced the original "get possible sets" block by this, seems more efficient and compact
// Also: binary count browsing is cool
// Input: sorted array of indices
private static List <List <int> > GetPossibleSetsFromIndices(List <int> list)
{
var array = list.ToArray();
int count = (int)Math.Pow(2, array.Length); //We know we'll iterate on 2^n possibilities
int min = (int)Math.Pow(2, 3) - 1; //start at b'...000000111' since it's the first result of length >= 3
int max = count - (int)Math.Pow(2, array.Length - 3); //end at b'11100000...' since it's the last result of length <= 3 (12% faster)
var results = new List <List <int> >();
if (list.Count < 3)
{
return(results);
}
int lastTile = -1;
int currentTile;
int nbTile;
bool ok;
for (int i = min; i <= max; i++)
{
var result = new List <int>();
string str = Convert.ToString(i, 2).PadLeft(array.Length, '0'); //we take i and convert it to a n bit integer, each value of i representing a possibility
nbTile = 0;
ok = true;
for (int j = 0; j < str.Length; j++)
{
if (str[j] == '1')
{
if (nbTile == 3)
{
ok = false;
break; // result is too large so let's stop here (might be the only useful optim here...)
}
currentTile = array[j];
if (currentTile - lastTile > 1 && lastTile >= 0)
{
ok = false;
break; // there is no way a group containing 'x,x+2' is a set
}
result.Add(currentTile);
lastTile = currentTile;
nbTile++;
}
}
if (ok && (U.is_chi(result) || U.is_pon(result)))
{
results.Add(result);
}
}
return(results);
}
//
// Find and return all valid set combinations in given suit
// :param tiles_34:
// :param first_index:
// :param second_index:
// :param hand_not_completed: in that mode we can return just possible shi or pon sets
// :return: list of valid combinations
//
List <List <List <int> > > find_valid_combinations(int[] tiles_34, int first_index, int second_index, bool hand_not_completed = false)
{
int count_of_sets;
var indices = new List <int>();
foreach (var x in Enumerable.Range(first_index, second_index + 1 - first_index))
{
if (tiles_34[x] > 0)
{
indices.AddRange(Enumerable.Repeat(x, tiles_34[x]).ToList());
}
}
var count_of_needed_combinations = Convert.ToInt32(indices.Count / 3);
if (indices.Count == 0 || count_of_needed_combinations == 0)
{
return(new List <List <List <int> > >
{
new List <List <int> >()
});
}
// indices are already sorted
var validMelds = GetPossibleSetsFromIndices(indices);
if (validMelds.Count == 0)
{
return(new List <List <List <int> > >
{
new List <List <int> >()
});
}
// simple case, we have count of sets == count of tiles
if (count_of_needed_combinations == validMelds.Count)
{
var toCheck = validMelds.Select(x => x.ToList() as IEnumerable <int>).Aggregate((z, y) => z.Concat(y));
if (toCheck.SequenceEqual(indices))
{
return(new List <List <List <int> > >()
{
validMelds
});
}
}
// filter and remove not possible pon sets
IEnumerable <List <int> > identicalSets;
foreach (var item in validMelds.ToArray().ToList())
{
if (U.is_pon(item))
{
count_of_sets = 1;
var count_of_tiles = 0;
while (count_of_sets > count_of_tiles)
{
count_of_tiles = (from x in indices
where x == item[0]
select x).ToList().Count / 3;
identicalSets = (from x in validMelds
where x[0] == item[0] && x[1] == item[1] && x[2] == item[2]
select x);
count_of_sets = identicalSets.Count();
if (count_of_sets > count_of_tiles)
{
validMelds.Remove(identicalSets.First());
}
}
}
}
// filter and remove not possible chi sets
foreach (var item in validMelds.ToArray().ToList())
{
if (U.is_chi(item))
{
count_of_sets = 5;
// TODO calculate real count of possible sets
var count_of_possible_sets = 4;
while (count_of_sets > count_of_possible_sets)
{
identicalSets = (from x in validMelds
where x[0] == item[0] && x[1] == item[1] && x[2] == item[2]
select x);
count_of_sets = identicalSets.Count();
if (count_of_sets > count_of_possible_sets)
{
validMelds.Remove(identicalSets.First());
}
}
}
}
// lit of chi\pon sets for not completed hand
if (hand_not_completed)
{
return(new List <List <List <int> > >()
{
validMelds
});
}
// hard case - we can build a lot of sets from our tiles
// for example we have 123456 tiles and we can build sets:
// [1, 2, 3] [4, 5, 6] [2, 3, 4] [3, 4, 5]
// and only two of them valid in the same time [1, 2, 3] [4, 5, 6]
int maxIndex = indices.Max() + 1;
var indexCount = new int[maxIndex];
foreach (var index in indices)
{
indexCount[index]++;
}
var possibleHands = GetPossibleHandsFromSets(validMelds, indexCount, count_of_needed_combinations);
return(possibleHands);
}