/// <summary>
/// Проверка и удаление нечастых поддеревьев
/// </summary>
/// <param name="freqList">Список поддеревьев</param>
/// <param name="support">Поддержка</param>
/// <param name="depth">Глубина</param>
private void PruneAfterConnection(FrequentSubtrees freqList, int support, int depth)
{
List <Tree> freqSubtreesAtDepth = freqList.GetFrequentsAtDepth(depth + 1);
foreach (Tree tree in freqSubtreesAtDepth)
{
tree.PruneAfterConnection(support, depth);
}
freqList.RemoveCannotBeExtended(depth + 1);
}
/// <summary>
/// Оценка частоты каждого поддерева из 1 и 2 узлов
/// </summary>
private void EvaluateFrequency()
{
foreach (Tree t1 in OneNodeTrees.Values.Where(t => t.IsFrequent))
{
FrequentSubtrees.AddFrequentSubtree(t1);
}
foreach (Tree t2 in TwoNodeTrees.Values.Where(t => t.IsFrequent))
{
FrequentSubtrees.AddFrequentSubtree(t2);
}
}
/// <summary>
/// Формирование поддеревьев из 1 и 2 узлов
/// </summary>
/// <param name="treeSet">Список кодировок деревьев</param>
/// <returns>Максимальная глубина деревьев</returns>
protected override int Generate1NodeAnd2NodesTrees(List <TextTreeEncoding> treeSet)
{
int maxDepth = -1;
foreach (TextTreeEncoding tree in treeSet)
{
Get1NodeAnd2NodesTrees(tree.Root, ref maxDepth);
}
FrequentSubtrees.SetDepth(maxDepth);
EvaluateFrequency();
return(maxDepth);
}
/// <summary>
/// Соединение 2 поддеревьев
/// </summary>
/// <param name="t2">Поддерево из 2 узлов</param>
/// <param name="tree">Поддерево с корнем в листе первого</param>
/// <param name="depth">Глубина</param>
private void Connect2Subtrees(Tree t2, Tree tree, int depth)
{
Debug.Assert(t2.Size == 2);
string[] preList = t2.ConnectDfsRepresentation(tree);
Tree child = Tree.Create(preList, true, SearchParams.Support);
ExtendedSubtrees.AddSubtree(child);
int depthC = depth + 1; // Глубина соединения
while (--depthC >= 0)
{
if (!t2.ContainsDepth(depthC))
{
continue;
}
int depthTree = depthC + 1;
if (!tree.ContainsDepth(depthTree))
{
continue;
}
foreach (TreeEntries tSet in t2[depthC].GetTreeEntries())
{
if (!tree.ContainsTreeAtDepth(depthTree, tSet.TreeId))
{
continue;
}
foreach (RootEntry root in tSet.GetRootEntries())
{
foreach (SubtreeEntry t2Entry in root.RightMostList)
{
if (!tree[depthTree][tSet.TreeId].RootDictionary.ContainsKey(t2Entry.SecondIndex))
{
continue;
}
var newEntry = t2Entry.Connect(tree[depthTree][tSet.TreeId][t2Entry.SecondIndex].FirstEntry);
child.AddEntry(newEntry);
}
}
}
}
if (!child.IsFrequent)
{
return;
}
FrequentSubtrees.AddFrequentSubtree(child);
child.Father = t2;
child.Mother = tree;
}
/// <summary>
/// Комбинирование 2 поддеревьев
/// </summary>
/// <param name="xTree">Первое поддерево</param>
/// <param name="yTree">Второе поддерево</param>
/// <param name="depth">Глубина</param>
/// <returns>Новое поддерево, полученное путем комбинирования</returns>
private Tree Combine2Subtrees(Tree xTree, Tree yTree, int depth)
{
string[] dfsList = xTree.CombineDfsRepresentation(yTree);
Tree child = Tree.Create(dfsList, false, SearchParams.Support);
ExtendedSubtrees.AddSubtree(child);
int curDepth = depth + 1;
while (--curDepth >= 0)
{
if (!xTree.ContainsDepth(curDepth) || !yTree.ContainsDepth(curDepth))
{
continue;
}
foreach (TreeEntries tSet in xTree[curDepth].GetTreeEntries())
{
if (!yTree.ContainsTreeAtDepth(curDepth, tSet.TreeId))
{
continue;
}
foreach (RootEntry root in tSet.GetRootEntries())
{
if (!yTree.ContainsRootIndex(curDepth, tSet.TreeId, root.RootIndex))
{
continue;
}
SubtreeEntry xEntry = xTree.GetEntry(curDepth, tSet.TreeId, root.RootIndex);
SubtreeEntry yEntry = yTree.GetFirstEntryAfterSpecifiedIndex(xEntry.Depth, xEntry.TreeId, xEntry.RootIndex, xEntry.RightMostIndex);
if (yEntry == null)
{
continue;
}
child.AddEntry(xEntry.Combine(yEntry));
}
}
}
if (!child.IsFrequent)
{
return(null);
}
FrequentSubtrees.AddFrequentSubtree(child);
child.Father = xTree;
child.Mother = yTree;
return(child);
}
/// <summary>
/// Соединение поддеревьев на заданной глубине
/// </summary>
/// <param name="depth">Глубина</param>
protected override void Connect(int depth)
{
List <Tree> connectableTrees = FrequentSubtrees.GetConnectableAtDepth(depth);
List <Tree> treesToBeConnected = FrequentSubtrees.GetToBeConnectableAtDepth(depth + 1);
foreach (Tree f2 in connectableTrees)
{
List <Tree> toBeConnected = SelectSubtreesOfSameRoot(f2.SecondSymbol, treesToBeConnected, depth + 1);
foreach (Tree t in toBeConnected)
{
string childDfsStr = f2.ConnectDfsRepresentation(t).ToDfsString();
if (ExtendedSubtrees.AlreadyExtended(childDfsStr))
{
continue;
}
if (!f2.HasNewConnectEntryAtDepth(t, depth))
{
continue;
}
Connect2Subtrees(f2, t, depth);
}
}
PruneAfterConnection(FrequentSubtrees, SearchParams.Support, depth);
}
/// <summary>
/// Обход с целью комбинирования поддеревьев
/// </summary>
/// <param name="xTree">Дерево, с которым производится комбинация</param>
/// <param name="yIndex">Индекс дерева в списке</param>
/// <param name="group">Список деревьев, которые можно комбинировать с xTree</param>
/// <param name="depth">Глубина</param>
private void Traversal(Tree xTree, int yIndex, IList <Tree> group, int depth)
{
Tree treeX = xTree;
Tree treeY = group[yIndex];
string childDfsStr = treeX.CombineDfsRepresentation(treeY).ToDfsString();
Tree child = null;
if (ExtendedSubtrees.AlreadyExtended(childDfsStr))
{
child = FrequentSubtrees.GetSubtreeAtDepth(childDfsStr, depth);
}
else if (treeX.HasNewCombineEntryAtDepth(treeY, depth))
{
child = Combine2Subtrees(treeX, treeY, depth);
}
if (child == null)
{
return;
}
for (int i = 0; i < group.Count; i++)
{
Traversal(child, i, group, depth);
}
}
/// <summary>
/// Комбинирование поддеревьев на заданной глубине
/// </summary>
/// <param name="depth">Глубина</param>
protected override void Combine(int depth)
{
List <Tree> combinableSubtrees = FrequentSubtrees.GetCombinableAtDepth(depth);
StartTraversal(combinableSubtrees, depth);
}