HDU 3460 Ancient Printer（java版）

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=3460

题型：字典树
思路：
答案 ans=nodesum*2-max+n
nodesum：字典树中除根节点外的节点总数
max：最长单词长度
n：单词个数

ps：不知道为啥用Scanner就过不了，io就过了，也没有tle）玄学

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StreamTokenizer;

public class Main {
    static StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
    static PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));

    public static int nextInt() throws IOException {
        in.nextToken();
        return (int) in.nval;
    }

    public static String next() throws IOException {
        in.nextToken();
        return (String) in.sval;
    }

    public static void main(String[] args) throws IOException {

        while (in.nextToken()!=StreamTokenizer.TT_EOF) {
            int n = (int)in.nval;
            Trie trie = new Trie();
            int max = 0;
            for (int i = 0; i < n; i++) {
                String str =next();
                if (str.length() > max) {
                    max = str.length();
                }
                trie.insert(str);
            }
            System.out.println(trie.sum * 2 - max + n);
        }

    }
}

class Trie {
    private int size = 26;
    private TrieNode root;
     int sum;

    public Trie() {
        root = new TrieNode();
        sum=0;
    }

    private class TrieNode {
        private int num;
        private TrieNode[] son;
        private boolean isEnd;
        private char val;

        public TrieNode() {
            num = 1;
            son = new TrieNode[size];
            isEnd = false;
        }
    }

    public void insert(String str) {
        if (str == null || str.length() == 0)
            return;
        TrieNode node = root;
        char letters[] = str.toCharArray();
        for (int i = 0, len = str.length(); i < len; i++) {
            int pos = letters[i] - 'a';
            if (node.son[pos] == null) {
                node.son[pos] = new TrieNode();
                node.son[pos].val = letters[i];
                this.sum++;
            } else {
                node.son[pos].num++;
            }
            node = node.son[pos];
        }
        node.isEnd = true;
    }
    public TrieNode getRoot() {
        return this.root;
    }
}