力扣208.实现前缀树（重要）

 208. 实现 Trie (前缀树) - 力扣（LeetCode） (leetcode-cn.com)

public class Trie {
    private Node1 root;

    public Trie() {
        root = new Node1();
    }

    public void insert(String word) {
        if(word==null)return;
        char[] chs = word.toCharArray();
        Node1 node = root;
        node.pass++;
        for (char ch : chs) {
            int index = ch - 'a';
            if (node.nexts[index] == null) {
                node.nexts[index] = new Node1();
            }
            node = node.nexts[index];
            node.pass++;
        }
        node.end++;
    }

    public boolean search(String word) {
        Node1 node = root;
        char[] chs = word.toCharArray();
        for (char ch : chs) {
            int index = ch - 'a';
            if (node.nexts[index] == null) return false;
            node = node.nexts[index];
        }
        return node.end >= 1;
    }

    public boolean startsWith(String prefix) {
        Node1 node = root;
        char[] chs = prefix.toCharArray();
        for (char ch : chs) {
            int index = ch - 'a';
            if (node.nexts[index] == null) return false;
            node = node.nexts[index];
        }
        return true;

    }
}

class Node1{
    public int pass;
    public int end;
    public Node1[] nexts;

    public Node1() {
        pass = 0;
        end = 0;
        nexts = new Node1[26];
    }
}

leetcode刷题总结之前缀树_algsup-CSDN博客