/*
* This method updates the {@code Key} when a word gets removed from the {@code Stack}
*
* Algorithm:
* 1. Pop one {@code Index} off the {@code Stack}
* 2. Re-input all other pairs still on the {@code Stack} to ensure that no older word had the same key/value pair
*
* @param stack the current {@code Stack} of words that have been solved
* @param words {@code List} of all the encrypted words
* @return the {@code Index} that got popped off the {@code Stack}
*/
public Index UpdateKey(IndexStack stack, List <string> words)
{
var removed = stack.Pop();
RemoveFromKey(words[removed.GetWi()]);
foreach (var index in stack)
{
var word = words[index.GetWi()];
var eWord = MyDictionary.GetInstance().GetWordSubset(word.Length, StringPattern.GetPattern(word)).ElementAt(index.GetMi());
AddToKey(word, eWord);
}
return(removed);
}
/*
* This method adds a word to the dictionary
*
* @param word word to be added to the dictionary
*/
public void AddWord(string word)
{
String pattern = StringPattern.GetPattern(word);
int key = word.Length;
if (!_words.ContainsKey(key))
{
_words.Add(key, new Dictionary <string, HashSet <string> >());
}
if (!_words[key].ContainsKey(pattern))
{
_words[key].Add(pattern, new HashSet <string>());
}
_words[key][pattern].Add(word);
}
/*
* This method checks pairs of an encrypted word with its set of decryptions against the {@code Key}
*
* @param word encrypted word
* @param index starting index in the list of decrypted matches
* @return the index of a pair that was successfully inserted into the key
*/
private int PickMatch(string word, int index)
{
var mySet = _dictionary.GetWordSubset(word.Length, StringPattern.GetPattern(word));
if (!mySet.Any())
{
throw new SystemException("No matches found for: " + word);
}
for (var i = index; i < mySet.Count; i++)
{
if (_key.AddToKey(word, mySet.ElementAt(i)))
{
return(i);
}
}
return(-1);
}