1 class Trie {
2 class TrieNode{
3 char label;
4 boolean flag;
5 TrieNode[] children;
6 TrieNode(char c){
7 label = c;
8 flag = false;
9 children = new TrieNode[26];
10 }
11 TrieNode(){
12 flag = false;
13 children = new TrieNode[26];
14 }
15 }
16 TrieNode root;
17
18 /** Initialize your data structure here. */
19 public Trie() {
20 root = new TrieNode();
21
22 }
23
24 /** Inserts a word into the trie. */
25 public void insert(String word) {
26 TrieNode node = root;
27 char[] arr = word.toCharArray();
28 for(char c : arr){
29 if(node.children[c-'a'] == null){
30 TrieNode child= new TrieNode(c);
31 node.children[c-'a'] = child;
32 node = child;
33 }else{
34 node = node.children[c-'a'];
35 }
36 }
37 node.flag = true;
38
39
40 }
41
42 /** Returns if the word is in the trie. */
43 public boolean search(String word) {
44 TrieNode node = root;
45 char[] arr = word.toCharArray();
46 for(char c : arr){
47 if(node.children[c-'a'] == null){
48 return false;
49 }else{
50 node = node.children[c-'a'];
51 }
52 }
53 return node.flag;
54
55 }
56
57 /** Returns if there is any word in the trie that starts with the given prefix. */
58 public boolean startsWith(String prefix) {
59 TrieNode node = root;
60 char[] arr = prefix.toCharArray();
61 for(char c : arr){
62 if(node.children[c-'a'] == null){
63 return false;
64 }else{
65 node = node.children[c-'a'];
66 }
67 }
68 return true;
69
70 }
71 }
