网站怎么做要多少钱上海市人大常委会
给定一个二维网格 board 和一个字典中的单词列表 words，找出所有同时在二维网格和字典中出现的单词。
单词必须按照字母顺序，通过相邻的单元格内的字母构成，其中“相邻”单元格是那些水平相邻或垂直相邻的单元格。同一个单元格内的字母在一个单词中不允许被重复使用。
示例:
输入: words =["oath","pea","eat","rain"]and board = [['o','a','a','n'],['e','t','a','e'],['i','h','k','r'],['i','f','l','v'] ]输出:["eat","oath"]
思路：
1、要打印所有情况，因此进行dfs，单词不允许重复，使用Set存储结果
2、将字典词存到字典树中
3、以二维数组每一个元素为单词第一个字母去遍历字典树，二维数组中的延伸方向为上下左右，使用visit数组保存是否访问过节点，使用数组边界判断避免越界
4、在dfs过程中判断单词所在字典树的节点end属性是否为true，为true添加该节点，继续dfs
5、dfs结束条件为树节点为null，返回false；
class Solution {//构建trie树节点public class TrieNode{private Map<Character,TrieNode> map = new HashMap<>();private boolean end;public TrieNode getSubNode(Character key){return map.get(key);}public void addSubNode(Character key,TrieNode value){map.put(key,value);}public boolean containsNode(Character key){return map.containsKey(key);}public boolean isEnd(){return end;}public void setEnd(boolean end){this.end=end;}}public List<String> findWords(char[][] board, String[] words) {TrieNode root=new TrieNode();root = insertWord(root,words);List<String> list = new ArrayList<>();Set<String> set = new HashSet<>();StringBuilder sb = new StringBuilder();boolean[][] visit = new boolean[board.length][board[0].length];int count=0;for(int i=0;i<board.length;i++){for(int j=0;j<board[0].length;j++){ searchWords(i,j,root,board,set,sb,visit);}}for(String s:set){list.add(s);}return list;}//插入字典单词到trie树public TrieNode insertWord(TrieNode root,String[] words){TrieNode tmpNode = root;for(int i=0;i<words.length;i++){tmpNode=root;for(int j=0;j<words[i].length();j++){char c = words[i].charAt(j);TrieNode node = tmpNode.getSubNode(c);if(node==null){node=new TrieNode();tmpNode.addSubNode(c,node);}tmpNode=node;if(j==words[i].length()-1){tmpNode.setEnd(true);}}}return root;}public boolean searchWords(int i,int j,TrieNode node,char[][] board,Set<String> list,StringBuilder sb,boolean[][] visit){boolean success=false;TrieNode tmpNode = node.getSubNode(board[i][j]);if(tmpNode==null){return false;}else{sb.append(board[i][j]);visit[i][j]=true;if(tmpNode.isEnd()){list.add(new String(sb));}if((i>0&&!visit[i-1][j])&&!success){success=searchWords(i-1,j,tmpNode,board,list,sb,visit);}if((i<board.length-1&&!visit[i+1][j])&&!success){success=searchWords(i+1,j,tmpNode,board,list,sb,visit);}if((j>0&&!visit[i][j-1])&&!success){success=searchWords(i,j-1,tmpNode,board,list,sb,visit);}if((j<board[0].length-1&&!visit[i][j+1])&&!success){success=searchWords(i,j+1,tmpNode,board,list,sb,visit);}sb.delete(sb.length()-1,sb.length());visit[i][j]=false;}return false;}
}