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class Trie {private Node root;
/** Initialize your data structure here. */
public Trie() {
this.root = new Node();
}/** Inserts a word into the trie. */
public void insert(String word) {
Node p = root;
for (int i = 0;
i < word.length();
i++) {
int dif = word.charAt(i) - 'a';
if (p.son[dif] == null) {
p.son[dif] = new Node();
}
p = p.son[dif];
}
p.isEnd = true;
}/** Returns if the word is in the trie. */
public boolean search(String word) {
Node p = root;
for (int i = 0;
i < word.length();
i++) {
int dif = word.charAt(i) - 'a';
if (p.son[dif] == null) {
return false;
} else {
p = p.son[dif];
}
}return p.isEnd;
}/** Returns if there is any word in the trie that starts with the given prefix. */
public boolean startsWith(String prefix) {
Node p = root;
for (int i = 0;
i < prefix.length();
i++) {
int dif = prefix.charAt(i) - 'a';
if (p.son[dif] == null) {
return false;
} else {
p = p.son[dif];
}
}return p != null;
}static class Node {
boolean isEnd;
Node[] son = new Node[26];
}
}/**
* Your Trie object will be instantiated and called as such:
* Trie obj = new Trie();
* obj.insert(word);
* boolean param_2 = obj.search(word);
* boolean param_3 = obj.startsWith(prefix);
*/
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