1268. 搜索推荐系统

给你一个产品数组 products 和一个字符串 searchWord ，products 数组中每个产品都是一个字符串。

请你设计一个推荐系统，在依次输入单词 searchWord 的每一个字母后，推荐 products 数组中前缀与 searchWord 相同的最多三个产品。如果前缀相同的可推荐产品超过三个，请按字典序返回最小的三个。

请你以二维列表的形式，返回在输入 searchWord 每个字母后相应的推荐产品的列表。

链接：https://leetcode-cn.com/problems/search-suggestions-system

import org.junit.Test;

import java.util.ArrayList;

import java.util.List;

public class Solution {
    private  class  TrieNode{
        boolean end = false;
        String str = null;
        int count = 0;
        TrieNode[] children = new TrieNode[26];
    }
    private class Trie{
        TrieNode root = new TrieNode();
        public void insert(String[] products){
            for (String str:
                    products) {
                insertWord(str);
            }
        }

        private void insertWord(String products) {
            TrieNode node = root;
            for(char c : products.toCharArray()){
                if(node.children[c - 'a'] == null){
                    node.children[c - 'a'] = new TrieNode();
                }
                node = node.children[c - 'a'];
            }
            if(node.end != true){
                node.end = true;
                node.str = products;
            }
            node.count++;
            System.out.println(node.count);
            System.out.println(node.str);
        }

        public List<List<String>> searchWord(String word){
            List<List<String>>  result = new ArrayList<>();
            for(int i = 1; i < word.length(); i++){
                result.add(search(word.substring(0, i)));
            }
            return result;
        }

        private List<String> search(String pattern) {
            List<String> result = new ArrayList<>();
            TrieNode node = root;
            for(char c : pattern.toCharArray()){
                if(node.children[c - 'a'] == null){
                    return result;
                }
                node = node.children[c - 'a'];
            }
            Solution(node,result);
            return  result;
        }

        private  void Solution(TrieNode root, List<String> result){
            if(root.end){
                for (int i = 0; i < root.count; i++) {
                    result.add(root.str);
                    if(result.size() == 3){
                        return;
                    }
                }
            }
            for (TrieNode node:
                    root.children) {
                if(node != null){ 
                    //System.out.println(node.str + "    " +node.end);
                    Solution(node, result);

                }
            }
            if(result.size() == 3){
                return;
            }
        }

    }

    public List<List<String>> suggestedProducts(String[] products, String searchWord) {
        Trie trie = new Trie();
        trie.insert(products);
        return trie.searchWord(searchWord);
    }

    @Test
    public  void  print(){
        String[] pro = {"mobile","mouse","mouse","moneypot","monitor","mousepad"};
        String searchWord = "mouse";
        List<List<String>> lists = new Solution().suggestedProducts(pro, searchWord);
        for(List list : lists){
            System.out.println(list.toString());
        }
    }
}