Leetcode 208:implement Trie (Prefix Tree)

Implement Trie (Prefix Tree)Total Accepted: 601 Total Submissions: 2396

Implement a trie with insert , search , and startsWith methods.

Note:
You may assume this all inputs is consist of lowercase letters a-z .

Ideas

Using HashMap to save children, use a bool variable to indicate if there is a word ending to this node.

[CODE]

Class Trienode {//Initialize your data structure here.    char c;    Boolean leaf;        Hashmap<character, trienode> children = new Hashmap<character, trienode> ();    Public Trienode (char c) {this.c = C; } public Trienode () {};}    public class Trie {private Trienode root;    Public Trie () {root = new Trienode ();    }//Inserts a word into the trie.        public void Insert (String word) {map<character, trienode> children = Root.children;            for (int i=0; i<word.length (); i++) {char c = word.charat (i);            Trienode T;            if (Children.containskey (c)) {T = Children.get (c);                } else {t = new Trienode (c);            Children.put (c, t);            } children = T.children;        if (I==word.length ()-1) t.leaf=true;    }}//Returns If the word is in the trie. public boolean search (String word) {Trienode t = Searchnode (Word);    return t!=null && t.leaf;    }//Returns If there is any word in the trie//that starts with the given prefix.    public boolean startsWith (String prefix) {return searchnode (prefix)! = NULL;        } private Trienode Searchnode (String word) {map<character, trienode> children = Root.children;        Trienode t = null;            for (int i=0; i<word.length (); i++) {char c = word.charat (i);            if (!children.containskey (c)) return null;            t = Children.get (c);        children = T.children;    } return t; }}//Your Trie object would be instantiated and called as such://Trie Trie = new Trie ();//Trie.insert ("somestring");//TR Ie.search ("key");

Leetcode 208:implement Trie (Prefix Tree)