string GetShortestPrefix(string str)
{
TireNode node = root;
for (int i = 0; i < str.Length; i++)
{
int index = str[i] - 'a';
if (node != null && node.isWord)
{
return(str.Substring(0, i + 1));
}
if (node.next[index] == null)
{
break;
}
else
{
node = node.next[index];
}
}
return(str);
}
bool CheckWord(TireNode root, int index, int count, string word)
{
if (index == word.Length && count > 1)
{
return(true);
}
TireNode cur = root;
int n = word.Length;
for (int i = index; i < n; i++)
{
if (cur.next[word[i] - 'a'] == null)
{
return(false);
}
if (cur.next[word[i] - 'a'].isWord)
{
if (CheckWord(root, i + 1, count + 1, word))
{
return(true);
}
}
cur = cur.next[word[i] - 'a'];
}
return(false);
}
public IList <string> FindAllConcatenatedWordsInADict(string[] words)
{
IList <string> res = new List <string>();
if (words == null || words.Length == 0)
{
return(res);
}
TireNode root = new TireNode();
foreach (string word in words)
{
if (word.Length > 0)
{
AddWord(root, word);
}
}
foreach (string word in words)
{
if (word.Length > 0)
{
if (CheckWord(root, 0, 0, word))
{
res.Add(word);
}
}
}
return(res);
}
public IList <string> WordBreak(string s, IList <string> wordDict)
{
IList <string> res = new List <string>();
if (string.IsNullOrEmpty(s) || wordDict.Count == 0)
{
return(res);
}
TireNode root = new TireNode();
foreach (string word in wordDict)
{
if (word.Length > 0)
{
AddWord(root, word);
}
}
List <string> ls = new List <string>();
TestWord(root, 0, s, ls, res);
return(res);
}
public void insert(string word)
{
TireNode node = root;
for (int i = 0; i < word.Length; i++)
{
int index = word[i] - 'a';
if (node.next[index] == null)
{
node.next[index] = new TireNode();
}
node = node.next[index];
}
node.isWord = true;
}
void AddWord(TireNode root, string str)
{
TireNode node = root;
for (int i = 0; i < str.Length; i++)
{
int index = str[i] - 'a';
if (node.next[index] == null)
{
node.next[index] = new TireNode();
}
node = node.next[index];
}
node.isWord = true;
}
void TestWord(TireNode root, int index, string word, List <string> ls, IList <string> res)
{
if (index == word.Length)
{
StringBuilder sb = new StringBuilder();
foreach (string s in ls)
{
sb.Append(s + " ");
}
string str = sb.ToString().TrimEnd();
if (!res.Contains(str))
{
res.Add(str);
}
return;
}
TireNode cur = root;
int n = word.Length;
for (int i = index; i < n; i++)
{
if (cur.next[word[i] - 'a'] == null)
{
return;
}
if (cur.next[word[i] - 'a'].isWord)
{
string ss = word.Substring(index, i - index + 1);
ls.Add(ss);
TestWord(root, i + 1, word, ls, res);
ls.RemoveAt(ls.Count - 1);
}
cur = cur.next[word[i] - 'a'];
}
}
public Tire()
{
root = new TireNode();
}