/// <summary>
/// Add word into the container using a starting index
/// </summary>
/// <param name="word">char array word</param>
/// <param name="start">starting index</param>
/// <param name="pageCount">pagecount of that word</param>
public override void Add(char[] word, int start, int pageCount)
{
if (word.Length == start)
{
End = true;
return;
}
int c = (int)word[start];
if (_next == null)
{
_next = new BurstNavigable[TRIE_WIDTH];
}
BurstNavigable target = _next[c];
if (target == null)
{
// always start with a container.
target = new MyContainer();
_next[c] = target;
}
else if (target.ShouldBurst) // else OK because there's never any need to burst a brand new bucket
{
target = BurstThisContainer(target);
_next[c] = target;
}
target.Add(word, start + 1, pageCount);
}
/// <summary>
/// Get 10 words from the current word
/// </summary>
/// <param name="temp">node or container</param>
/// <param name="word">string based prefix</param>
/// <returns>10 words from that prefix</returns>
public List <string> GetWords(BurstNavigable temp, string word)
{
List <string> result = new List <string>();
GetWords(temp, word.ToCharArray(), result, 0, "");
return(result);
}
/// <summary>
/// Burst the container, replace it with a node and the most common character will be the child of that node
/// anything left will be put in containers approriately
/// </summary>
/// <param name="temp">container</param>
/// <returns>a node with an array of children that are either a node or container</returns>
public MyTrieNode BurstThisContainer(BurstNavigable temp)
{
MyTrieNode node = new MyTrieNode();
IEnumerator <Word> _enumerator = temp.GetChildren().GetEnumerator();
while (_enumerator.MoveNext())
{
node.Add(_enumerator.Current.content.ToCharArray(), 0, _enumerator.Current.pageCount);
}
return(node);
}
/// <summary>
/// Get words from the container or node. If node then we continue to traverse down, if not
/// we will just add all the word in the container into the list
/// </summary>
/// <param name="temp">node or container</param>
/// <param name="result">list of the words</param>
/// <param name="resultString">result string to be concat with what is in the container</param>
private void GetWords(BurstNavigable temp, List <string> result, string resultString)
{
if (result.Count >= 10)
{
return;
}
if (temp == null)
{
return;
}
else
{
if (temp.End)
{//if end then add
if (!result.Contains(resultString))
{
result.Add(resultString);
}
}
if (temp.getType() == 'n') //if node traverse every node in the children
{
BurstNavigable[] array = temp.GetNexts();
for (int i = 0; i < array.Length; i++)
{
GetWords(array[i], result, resultString + (char)i);
}
}
else //if container, add into all the string inside the container
{
IEnumerator <Word> _enumerator = temp.GetChildren().GetEnumerator();;
while (_enumerator.MoveNext())
{
if (result.Count >= 10)
{
break;
}
if (!result.Contains(resultString + _enumerator.Current.content))
{
result.Add(resultString + _enumerator.Current.content);
}
}
}
}
}
/// <summary>
/// Will get back all the suggestions that is the same length with the prefix and within 1,2 Levenshtein Distance
/// </summary>
/// <param name="temp">node or conatiner</param>
/// <param name="result">list to store all the string</param>
/// <param name="resultString">result string to be compared with prefix</param>
/// <param name="prefix">word input by the user</param>
/// <param name="limit">limit</param>
/// <param name="start">starting index</param>
private void GetSuggestionsWithLimits(BurstNavigable temp, List <string> result, string resultString, string prefix, int limit, int start)
{
if (temp == null)
{
return;
}
if (result.Count >= 10)
{
return;
}
if (start == limit)
{
int distance = CalcLevenshteinDistance(prefix, resultString);
if (temp.End && (distance == 1 || distance == 2))
{
if (!result.Contains(resultString))
{
result.Add(resultString);
}
return;
}
if (distance == 1 || distance == 2)
{
if (result.Count < 10)
{
if (!result.Contains(resultString))
{
result.Add(resultString);
}
}
}
return;
}
if (temp.getType() == 'n') //if node traverse every node in the children
{
BurstNavigable[] array = temp.GetNexts();
for (int i = 0; i < array.Length; i++)
{
GetSuggestionsWithLimits(array[i], result, resultString + (char)i, prefix, limit, start + 1);
}
}
else //if container, add into all the string inside the container
{
IEnumerator <Word> _enumerator = temp.GetChildren().GetEnumerator();;
while (_enumerator.MoveNext())
{
if (result.Count >= 10)
{
break;
}
string left = "";
for (int i = start; i < limit && i < _enumerator.Current.content.Length; i++)
{
left = left + _enumerator.Current.content[i];
}
resultString = resultString + left;
int distance = CalcLevenshteinDistance(prefix, resultString);
if (distance == 1 || distance == 2)
{
if (!result.Contains(resultString))
{
result.Add(resultString);
}
}
}
}
}
/// <summary>
/// get all the prefix suggestion from the input word
/// </summary>
/// <param name="temp">node or container</param>
/// <param name="word">character array of the word</param>
/// <param name="result">result list</param>
/// <param name="start">starting index</param>
/// <param name="resultString">resulting string to be concat with what is left in the container before adding</param>
private void GetWords(BurstNavigable temp, char[] word, List <string> result, int start, string resultString)
{
if (temp == null)
{
return;
}
if (start == word.Length)
{
//if this is a node, traverse through each node of the children to get all the children nodes
if (temp.getType() == 'n')
{
if (temp.End)
{
if (!result.Contains(resultString))
{
result.Add(resultString);
}
}
if (result.Count >= 10)
{
return;
}
else
{
BurstNavigable[] array = temp.GetNexts();
for (int i = 0; i < array.Length; i++)
{
GetWords(array[i], result, resultString + (char)i);
}
}
}
else //if not just add all the words of the container into the list and return;
{
IEnumerator <Word> _enumerator = temp.GetChildren().GetEnumerator();;
while (_enumerator.MoveNext())
{
if (result.Count >= 10)
{
break;
}
if (!result.Contains(resultString + _enumerator.Current.content))
{
result.Add(resultString + _enumerator.Current.content);
}
}
}
}
else if (temp.getType() == 'n')
{
int c = (int)word[start];
temp = temp.GetChild(c);
if (temp == null)
{
return;
}
GetWords(temp, word, result, start + 1, resultString + word[start]);
}
else
{
string left = "";
for (int i = start; i < word.Length; i++)
{
left = left + word[i];
}
IEnumerator <Word> _enumerator = temp.GetChildren().GetEnumerator();;
while (_enumerator.MoveNext())
{
if (result.Count >= 10)
{
break;
}
if (_enumerator.Current.content.StartsWith(left))
{
if (!result.Contains(resultString + _enumerator.Current.content))
{
result.Add(resultString + _enumerator.Current.content);
}
}
}
}
}