public void ReplaceChainElement(int indexOfChainEntry, T newElement)
{
_chain[indexOfChainEntry] =
new ListChainElement
{
Element = newElement,
NextElementIndex = _chain[indexOfChainEntry].NextElementIndex,
PreviousElementIndex = _chain[indexOfChainEntry].PreviousElementIndex
};
}
public bool RemoveChainElement(int number, int indexOfChainEntry)
{
// returns true, if indexOfChainEntry is the only element in the chain.
_freedChainIndexes.Push(indexOfChainEntry);
var chainElement = _chain[indexOfChainEntry];
if (chainElement.PreviousElementIndex == -1 && chainElement.NextElementIndex == -1)
{
// this is the only element
_firstChainElementOfChainNumber[number] = -1;
_lastChainElementOfChainNumber[number] = -1;
return(true);
}
var indexOfNextChainElement = chainElement.NextElementIndex;
var indexOfPreviousChainElement = chainElement.PreviousElementIndex;
if (indexOfNextChainElement != -1)
{
// the current element has a successor
_chain[indexOfNextChainElement] =
new ListChainElement
{
Element = _chain[indexOfNextChainElement].Element,
NextElementIndex = _chain[indexOfNextChainElement].NextElementIndex,
PreviousElementIndex = indexOfPreviousChainElement
};
}
else
{
//removed the last element
_lastChainElementOfChainNumber[number] = indexOfPreviousChainElement;
}
if (indexOfPreviousChainElement != -1)
{
// the current element has a predecessor
_chain[indexOfPreviousChainElement] =
new ListChainElement
{
Element = _chain[indexOfPreviousChainElement].Element,
NextElementIndex = indexOfNextChainElement,
PreviousElementIndex = _chain[indexOfPreviousChainElement].PreviousElementIndex
};
}
else
{
//removed the first element
_firstChainElementOfChainNumber[number] = indexOfNextChainElement;
}
return(false);
}
public void StartChain(int indexOfNewChainEntry, int number, T newElement)
{
Assert.That(_firstChainElementOfChainNumber[number] == -1, "Chain should be empty");
_firstChainElementOfChainNumber[number] = indexOfNewChainEntry;
_lastChainElementOfChainNumber[number] = indexOfNewChainEntry;
_chain[indexOfNewChainEntry] =
new ListChainElement
{
Element = newElement,
NextElementIndex = -1,
PreviousElementIndex = -1
};
}
public void RemoveSuccessors(int number, int indexOfChainEntryToKeep)
{
Assert.That(indexOfChainEntryToKeep != -1, "ChainElement must exist");
var indexOfChainEntryToDelete = _chain[indexOfChainEntryToKeep].NextElementIndex;
_lastChainElementOfChainNumber[number] = indexOfChainEntryToKeep;
_chain[indexOfChainEntryToKeep] =
new ListChainElement
{
Element = _chain[indexOfChainEntryToKeep].Element,
NextElementIndex = -1,
PreviousElementIndex = _chain[indexOfChainEntryToKeep].PreviousElementIndex
};
while (indexOfChainEntryToDelete != -1)
{
_freedChainIndexes.Push(indexOfChainEntryToDelete);
indexOfChainEntryToDelete = _chain[indexOfChainEntryToDelete].NextElementIndex;
}
}
public void InsertChainElement(int indexOfNewChainEntry, int number, int indexOfPreviousChainElement, T newElement)
{
var previousNextElement = _chain[indexOfPreviousChainElement].NextElementIndex;
var previousPreviousElement = _chain[indexOfPreviousChainElement].PreviousElementIndex;
_chain[indexOfNewChainEntry] =
new ListChainElement
{
Element = newElement,
NextElementIndex = previousNextElement,
PreviousElementIndex = indexOfPreviousChainElement
};
_chain[indexOfPreviousChainElement] =
new ListChainElement
{
Element = _chain[indexOfPreviousChainElement].Element,
NextElementIndex = indexOfNewChainEntry,
PreviousElementIndex = previousPreviousElement
};
if (previousNextElement == -1)
{
_lastChainElementOfChainNumber[number] = indexOfNewChainEntry;
}
else
{
_chain[previousNextElement] =
new ListChainElement
{
Element = _chain[previousNextElement].Element,
NextElementIndex = _chain[previousNextElement].NextElementIndex,
PreviousElementIndex = indexOfNewChainEntry
};
}
}
