Java中实现双数组Trie树实例

import java.util.arraylist;
import java.util.hashmap;
import java.util.map;
import java.util.arrays;

public class doublearraytrie {
 final char end_char = '\0';
 final int default_len = 1024;
 int base[]  = new int [default_len];
 int check[] = new int [default_len];
 char tail[] = new char [default_len];
 int pos = 1;
 map<character ,integer> charmap = new hashmap<character,integer>();
 arraylist<character> charlist = new arraylist<character>();
 
 public doublearraytrie()
 {
  base[1] = 1;
  
  charmap.put(end_char,1);
  charlist.add(end_char);
  charlist.add(end_char);
  for(int i=0;i<26;++i)
  {
   charmap.put((char)('a'+i),charmap.size()+1);
   charlist.add((char)('a'+i));
  }
  
 }
 private void extend_array()
 {
  base = arrays.copyof(base, base.length*2);
  check = arrays.copyof(check, check.length*2);
 }
 
 private void extend_tail()
 {
  tail = arrays.copyof(tail, tail.length*2);
 }
 
 private int getcharcode(char c)
 {
  if (!charmap.containskey(c))
  {
   charmap.put(c,charmap.size()+1);
   charlist.add(c);
  }
  return charmap.get(c);
 }
 private int copytotailarray(string s,int p)
 {
  int _pos = pos;
  while(s.length()-p+1 > tail.length-pos)
  {
   extend_tail();
  }
  for(int i=p; i<s.length();++i)
  {
   tail[_pos] = s.charat(i);
   _pos++;
  }
  return _pos;
 }
 
 private int x_check(integer []set)
 {
  for(int i=1; ; ++i)
  {
   boolean flag = true;
   for(int j=0;j<set.length;++j)
   {
    int cur_p = i+set[j];
    if(cur_p>= base.length) extend_array();
    if(base[cur_p]!= 0 || check[cur_p]!= 0)
    {
     flag = false;
     break;
    }
   }
   if (flag) return i;
  }
 }
 
 private arraylist<integer> getchildlist(int p)
 {
  arraylist<integer> ret = new arraylist<integer>();
  for(int i=1; i<=charmap.size();++i)
  {
   if(base[p]+i >= check.length) break;
   if(check[base[p]+i] == p)
   {
    ret.add(i);
   }
  }
  return ret;
 }
 
 private boolean tailcontainstring(int start,string s2)
 {
  for(int i=0;i<s2.length();++i)
  {
   if(s2.charat(i) != tail[i+start]) return false;
  }
  
  return true;
 }
 private boolean tailmatchstring(int start,string s2)
 {
  s2 += end_char;
  for(int i=0;i<s2.length();++i)
  {
   if(s2.charat(i) != tail[i+start]) return false;
  }
  return true;
 }
 
 
 public void insert(string s) throws exception
 {
  s += end_char;
  
  int pre_p = 1;
  int cur_p;
  for(int i=0; i<s.length(); ++i)
  {
   //获取状态位置
   cur_p = base[pre_p]+getcharcode(s.charat(i));
   //如果长度超过现有，拓展数组
   if (cur_p >= base.length) extend_array();
   
   //空闲状态
   if(base[cur_p] == 0 && check[cur_p] == 0)
   {
    base[cur_p] = -pos;
    check[cur_p] = pre_p;
    pos = copytotailarray(s,i+1);
    break;
   }else
   //已存在状态
   if(base[cur_p] > 0 && check[cur_p] == pre_p)
   {
    pre_p = cur_p;
    continue;
   }else
   //冲突 1：遇到 base[cur_p]小于0的，即遇到一个被压缩存到tail中的字符串
   if(base[cur_p] < 0 && check[cur_p] == pre_p)
   {
    int head = -base[cur_p];
    
    if(s.charat(i+1)== end_char && tail[head]==end_char) //插入重复字符串
    {
     break;
    }
    
    //公共字母的情况，因为上一个判断已经排除了结束符，所以一定是2个都不是结束符
    if (tail[head] == s.charat(i+1))
    {
     int avail_base = x_check(new integer[]{getcharcode(s.charat(i+1))});
     base[cur_p] = avail_base;
     
     check[avail_base+getcharcode(s.charat(i+1))] = cur_p;
     base[avail_base+getcharcode(s.charat(i+1))] = -(head+1);
     pre_p = cur_p;
     continue;
    }
    else
    {
     //2个字母不相同的情况，可能有一个为结束符
     int avail_base ;
     avail_base = x_check(new integer[]{getcharcode(s.charat(i+1)),getcharcode(tail[head])});
     
     base[cur_p] = avail_base;
     
     check[avail_base+getcharcode(tail[head])] = cur_p;
     check[avail_base+getcharcode(s.charat(i+1))] = cur_p;
     
     //tail 为end_flag 的情况
     if(tail[head] == end_char)
      base[avail_base+getcharcode(tail[head])] = 0;
     else
      base[avail_base+getcharcode(tail[head])] = -(head+1);
     if(s.charat(i+1) == end_char)
      base[avail_base+getcharcode(s.charat(i+1))] = 0;
     else
      base[avail_base+getcharcode(s.charat(i+1))] = -pos;
     
     pos = copytotailarray(s,i+2);
     break;
    }
   }else
   //冲突2：当前结点已经被占用，需要调整pre的base
   if(check[cur_p] != pre_p)
   {
    arraylist<integer> list1 = getchildlist(pre_p);
    int tobeadjust;
    arraylist<integer> list = null;
    if(true)
    {
     tobeadjust = pre_p;
     list = list1;
    }
    
    int origin_base = base[tobeadjust];
    list.add(getcharcode(s.charat(i)));
    int avail_base = x_check((integer[])list.toarray(new integer[list.size()]));
    list.remove(list.size()-1);
    
    base[tobeadjust] = avail_base;
    for(int j=0; j<list.size(); ++j)
    {
     //bug
     int tmp1 = origin_base + list.get(j);
     int tmp2 = avail_base + list.get(j);
     
     base[tmp2] = base[tmp1];
     check[tmp2] = check[tmp1];
     
     //有后续
     if(base[tmp1] > 0)
     {
      arraylist<integer> subsequence = getchildlist(tmp1);
      for(int k=0; k<subsequence.size(); ++k)
      {
       check[base[tmp1]+subsequence.get(k)] = tmp2;
      }
     }
     
     base[tmp1] = 0;
     check[tmp1] = 0;
    }
    
    //更新新的cur_p
    cur_p = base[pre_p]+getcharcode(s.charat(i));
    
    if(s.charat(i) == end_char)
     base[cur_p] = 0;
    else
     base[cur_p] = -pos;
    check[cur_p] = pre_p;
    pos = copytotailarray(s,i+1);
    break;
   }
  }
 }
 
 public boolean exists(string word)
 {
  int pre_p = 1;
  int cur_p = 0;
  
  for(int i=0;i<word.length();++i)
  {
   cur_p = base[pre_p]+getcharcode(word.charat(i));
   if(check[cur_p] != pre_p) return false;
   if(base[cur_p] < 0)
   {
    if(tailmatchstring(-base[cur_p],word.substring(i+1)))
     return true;
    return false;
   }
   pre_p = cur_p;
  }
  if(check[base[cur_p]+getcharcode(end_char)] == cur_p)
   return true;
  return false;
 }
 
 //内部函数，返回匹配单词的最靠后的base index，
 class findstruct
 {
  int p;
  string prefix="";
 }
 private findstruct find(string word)
 {
  int pre_p = 1;
  int cur_p = 0;
  findstruct fs = new findstruct();
  for(int i=0;i<word.length();++i)
  {
   // bug
   fs.prefix += word.charat(i);
   cur_p = base[pre_p]+getcharcode(word.charat(i));
   if(check[cur_p] != pre_p)
   {
    fs.p = -1;
    return fs;
   }
   if(base[cur_p] < 0)
   {
    if(tailcontainstring(-base[cur_p],word.substring(i+1)))
    {
     fs.p = cur_p;
     return fs;
    }
    fs.p = -1;
    return fs;
   }
   pre_p = cur_p;
  }
  fs.p =  cur_p;
  return fs;
 }
 
 public arraylist<string> getallchildword(int index)
 {
  arraylist<string> result = new arraylist<string>();
  if(base[index] == 0)
  {
   result.add("");
   return result;
  }
  if(base[index] < 0)
  {
   string r="";
   for(int i=-base[index];tail[i]!=end_char;++i)
   {
    r+= tail[i];
   }
   result.add(r);
   return result;
  }
  for(int i=1;i<=charmap.size();++i)
  {
   if(check[base[index]+i] == index)
   {
    for(string s:getallchildword(base[index]+i))
    {
     result.add(charlist.get(i)+s);
    }
    //result.addall(getallchildword(base[index]+i));
   }
  }
  return result;
 }
 
 public arraylist<string> findallwords(string word)
 {
  arraylist<string> result = new arraylist<string>();
  string prefix = "";
  findstruct fs = find(word);
  int p = fs.p;
  if (p == -1) return result;
  if(base[p]<0)
  {
   string r="";
   for(int i=-base[p];tail[i]!=end_char;++i)
   {
    r+= tail[i];
   }
   result.add(fs.prefix+r);
   return result;
  }
  
  if(base[p] > 0)
  {
   arraylist<string> r =  getallchildword(p);
   for(int i=0;i<r.size();++i)
   {
    r.set(i, fs.prefix+r.get(i));
   }
   return r;
  }
  
  return result;
 }
 
}

import javax.xml.crypto.data;

public class main {

 public static void main(string[] args) throws exception {
  arraylist<string> words = new arraylist<string>();
  bufferedreader reader = new bufferedreader(new inputstreamreader(new fileinputstream("e:/兔子的试验学习中心[课内]/acm大赛/acm第四届校赛/e命令提示/words3.dic")));
  string s;
  int num = 0;
  while((s=reader.readline()) != null)
  {
   words.add(s);
   num ++;
  }
  doublearraytrie dat = new doublearraytrie();
  
  for(string word: words)
  {
   dat.insert(word);
  }
  
  system.out.println(dat.base.length);
  system.out.println(dat.tail.length);
  
  scanner sc = new scanner(system.in);
  while(sc.hasnext())
  {
   string word = sc.next();
   system.out.println(dat.exists(word));
   system.out.println(dat.findallwords(word));
  }
  
 }

}