标签：cal 思考 returns class poi code sum initial any
Implement a trie with insert, search, and startsWith methods.
Note:
You may assume that all inputs are consist of lowercase letters a-z.
public class Trie {
Trie[] children;
int count = 0;
/** Initialize your data structure here. */
public Trie() {
children = new Trie[26];
}
/** Inserts a word into the trie. */
public void insert(String word) {
if (word.equals("")) {
count++;
}
Trie cur = this;
int i = 0;
while (i < word.length()) {
if (cur.children[word.charAt(i) - ‘a‘] == null) {
cur.children[word.charAt(i) - ‘a‘] = new Trie();
}
cur = cur.children[word.charAt(i) - ‘a‘];
i++;
}
cur.count++;
}
/** Returns if the word is in the trie. */
public boolean search(String word) {
Trie cur = this;
int i = 0;
while (cur != null && i < word.length()) {
cur = cur.children[word.charAt(i) - ‘a‘];
i++;
}
if (cur == null || cur.count == 0) {
return false;
}
return true;
}
/** Returns if there is any word in the trie that starts with the given prefix. */
public boolean startsWith(String prefix) {
Trie cur = this;
int i = 0;
while (cur != null && i < prefix.length()) {
cur = cur.children[prefix.charAt(i) - ‘a‘];
i++;
}
if (cur == null) {
return false;
}
return true;
}
}
/**
* 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);
*/
208. Implement Trie (Prefix Tree)
标签：cal 思考 returns class poi code sum initial any
原文地址：http://www.cnblogs.com/yuchenkit/p/7223486.html
