[Leedcode 211] ADD and Search word-data structure design

Design a data structure that supports the following and the operations:

void Addword (Word) bool Search (word)

Search (Word) can search a literal word or a regular expression string containing only letters a-z or . . A . means it can represent any one letter.

For example:

Addword ("Bad") Addword ("Dad") Addword ("Mad") Search ("pad"), Falsesearch ("bad"), Truesearch (". Ad") Truesearch ("B..")-True

 Public classWorddictionary {//the transformation of the dictionary tree, each node holds a character, and a collection of child nodes: list, and whether the tag is a isend Boolean of the tail node//both the Add and search methods are implemented using recursion    PrivateNode Root; Static classnode{ PublicCharacter Val;  PublicList<node>children;  Public BooleanIsend;  PublicNode (Character val) { This. val=Val; Children=NewArraylist<node>(); Isend=false; }    }     PublicWorddictionary () {root=NewNode ('/'); }    //Adds A word into the data structure.     Public voidAddword (String word) {Addword (word,root); }     Public voidAddword (String word,node root) {if(Word.length () ==0) {Root.isend=true; return ; } Node cur=NULL;//represents a matching new node        if(Root.children.size () >0){             for(Node node:root.children) {if(Node.val==word.charat (0) ) {cur=node;  Break; }            }                    }        if(cur!=NULL) Addword (word.substring (1), cur); Else{cur=NewNode (Word.charat (0));            Root.children.add (cur); Addword (Word.substring (1), cur); }    }    //Returns If the word is in the data structure. A Word could//contain the dot character '. ' to represent.     Public BooleanSearch (String word) {returnsearch (word,root); }    Private BooleanSearch (String word,node root) {if(Word.length () ==0){            returnroot.isend==true; }        if(root.children==NULL)return false; if(Word.charat (0) = = '. '){             for(Node node:root.children) {BooleanRet=search (word.substring (1), node); if(ret)return true; }            return false; }Else{             for(Node node:root.children) {if(Node.val==word.charat (0)){                    returnSearch (word.substring (1), node); }            }            return false; }            }}//Your Worddictionary object would be instantiated and called as such://worddictionary worddictionary = new Worddictionary ();//Worddictionary.addword ("word");//Worddictionary.search ("pattern");

[Leedcode 211] ADD and Search word-data structure design