题解 | #HJ066 配置文件恢复#

import java.util.*;

/**
 * HJ66 配置文件恢复 - 中等
 */
public class Main {

    public static final String UNKNOWN_COMMAND = "unknown command";
    static Map<String, String> map = new HashMap<String, String>() {
        {
            put("reset", "reset what");
            put("reset board", "board fault");
            put("board add", "where to add");
            put("board delete", "no board at all");
            put("reboot backplane", "impossible");
            put("backplane abort", "install first");
        }
    };

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            String cmd = sc.nextLine();
            calculate(cmd);
        }
        sc.close();
    }

    public static void calculate(String cmd) {
        String[] cmdArr = cmd.split(" ");
        if (cmdArr.length == 1) {
            if ("reset".startsWith(cmd)) {
                System.out.println(map.get("reset"));
            } else {
                System.out.println(UNKNOWN_COMMAND);
            }
        } else {
            String result = UNKNOWN_COMMAND;
            int count = 0;
            for (String key : map.keySet()) {
                String[] keyArr = key.split(" ");
                if (keyArr.length > 1 && keyArr[0].startsWith(cmdArr[0])
                        && keyArr[1].startsWith(cmdArr[1])) {
                    result = map.get(key);
                    count++;
                }
            }
            System.out.println(count > 1 ? UNKNOWN_COMMAND : result);
        }
    }
}