Algorithm 字典(排序)树Trie

package edu.whu.cs.basic;

import java.util.ArrayList;

public class Trie{
    public  class TrieNode{
        public int path;
        public int end;
        public TrieNode[] map;
        public String word;
        public TrieNode() {
            super();
            this.path = 0;
            this.end = 0;
            this.map = new TrieNode[26];
            this.word = null;
        }
        
        
    }
   private TrieNode root;
   public Trie(){
       root  = new TrieNode();
   }
   public void insert(String word){
       if(word == null){
           return ;
       }
       char[] chs = word.toCharArray();
       TrieNode node = root;
       int index = 0;
       int i = 0;
       while(i<chs.length){
           index = chs[i] - 'a';
           if(node.map[index] == null){
               node.map[index] = new TrieNode();
               if(node.word == null){
                   node.map[index].word = String.valueOf(chs[i]);
               }else{
                   node.map[index].word = node.word + chs[i];
               }
           }
           node = node.map[index];
           node.path++;
           i++;
       }
       node.end ++;
   }
   
   public void delete(String word){
       if(search (word)){
           char[] chs = word.toCharArray();
           TrieNode node = root;
           int index = 0;
           for(int i=0;i<chs.length;i++){
               index = chs[i] - 'a';
               if(node.map[index].path-- == 1){
                   node.map[index] = null;
               }
               node = node.map[index];
               node.path++;
           }
           node.end --;
       }
   }
    public boolean search(String word) {
         if(word == null){
             return false;
         }
         char[] chs = word.toCharArray();
         TrieNode node = root;
         int index = 0;
         for(int i=0;i<chs.length;i++){
             index = chs[i] - 'a';
             if(node.map[index] == null){
                 return false;
             }
             node = node.map[index];
         }
         return node.end != 0;
    }
    
    public int prefixNumber(String pre) {
        if(pre == null){
            return 0;
        }
        char[] chs = pre.toCharArray();
        TrieNode node = root;
        int index = 0;
        for(int i=0;i<chs.length;i++){
            index = chs[i] - 'a';
            if(node.map[index] == null){
                return 0;
            }
            node = node.map[index];
        }
        return node.path;
   }
    
    public void output(TrieNode node,ArrayList<String> list){
        if(node != null){
            int counts = node.end;
            while(counts != 0){
                list.add(node.word.toString());
                counts--;
            }
            for(int i=0;i<node.map.length;i++){
                output(node.map[i],list);
            }
        }
    }
    
    public static void main(String[] args) {
        String[] str = { "zbdfasd",
                "zbcfd",
                "zbcdfdasfasf",
                "abcdaf",
                "defdasfa",
                "fedfasfd",
                "dfdfsa",
                "dfdfsa",
                "dfdfsa",
                "dfdfsa",
                "dfdfsa",
                "dadfd",
                "dadfd",
                "dadfd",
                "abcfdfa",
                "fbcdfd",
                "abcdaf"
        };
        Trie trie = new Trie();
        for(int i=0;i<str.length;i++){
            trie.insert(str[i]);
        }
        ArrayList<String> list = new ArrayList<String>();
        trie.output(trie.root, list);
        for(int i=0;i<list.size();i++)
            System.out.println(list.get(i));
    }
   
}