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_208.java
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_208.java
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package com.fishercoder.solutions;
public class _208 {
public static class Solution1 {
public static class TrieNode {
boolean isWord;
TrieNode[] children = new TrieNode[26];
}
public static class Trie {
private TrieNode root;
public Trie() {
root = new TrieNode();//initialize root to be an empty char, this is a common practice as how Wiki defines Trie data structure as well
}
// Inserts a word into the trie.
public void insert(String word) {
TrieNode node = root;
for (int i = 0; i < word.length(); i++) {
if (node.children[word.charAt(i) - 'a'] == null) {
node.children[word.charAt(i) - 'a'] = new TrieNode();
}
node = node.children[word.charAt(i) - 'a'];
}
node.isWord = true;
}
// Returns if the word is in the trie.
public boolean search(String word) {
TrieNode node = root;
for (int i = 0; i < word.length(); i++) {
if (node.children[word.charAt(i) - 'a'] == null) {
return false;
}
node = node.children[word.charAt(i) - 'a'];
}
return node.isWord;
}
// Returns if there is any word in the trie
// that starts with the given prefix.
public boolean startsWith(String prefix) {
TrieNode node = root;
for (int i = 0; i < prefix.length(); i++) {
if (node.children[prefix.charAt(i) - 'a'] == null) {
return false;
}
node = node.children[prefix.charAt(i) - 'a'];
}
return true;
}
}
// Your Trie object will be instantiated and called as such:
// Trie trie = new Trie();
// trie.insert("somestring");
// trie.search("key");
}
}