poj 2001(trie)

/**
 * poj 2001
 * trie字典树
 * 題意：给出n个单词（1<=n<=1000），求出每个单词的非公共前缀，如果没有，则输出自己。
 */
import java.util.*;

class Node {
	int num;
	Node[] child = new Node[26];
}

public class Main {

	final int MAX = 1005;
	Scanner sc = new Scanner(System.in);
	char[][] str = new char[MAX][21];
	Node root = new Node();

	void insert(char[] s) {
		Node node = root;
		for (int i = 0; i < s.length; i++) {
			int id = s[i] - 'a';
			if (node.child[id] == null)
				node.child[id] = new Node();
			node = node.child[id];
			node.num++;
		}
	}

	void find(char[] s) {
		Node node = root;
		System.out.print(new String(s) + " ");
		for (int i = 0; i < s.length; i++) {
			System.out.print(s[i]);
			int id = s[i] - 'a';
			if (node.child[id].num == 1)
				break;
			node = node.child[id];
		}
		System.out.println();
	}

	void init() {
		char[] s = new char[21];
		int index = 0;
		while (sc.hasNext()) {
			s = sc.next().toCharArray();
			str[index++] = s;
			insert(s);
		}
		for (int i = 0; i < index; i++) {
			find(str[i]);
		}
	}

	public static void main(String[] args) throws Exception {
		new Main().init();
	}
}