题解 | #配置文件恢复#

//贴个自己写的，应该算是比较好理解的了

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String[] cmds1 = new String[] {"reset", "reset", "board", "board", "reboot", "backplane"};
        String[] cmds2 = new String[] {" ", "board", "add", "delete", "backplane", "abort"};
        String[] operations = new String[] {"reset what", "board fault",
                                            "where to add", "no board at all", "impossible", "install first"
                                           };
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            String[] str = in.nextLine().split(" ");

            String cmd1 = str[0], cmd2 = str.length == 1 ? " " : str[1];

            int count = 0, res_idx = -1;
            for (int idx = 0; idx < 6; idx++) {
                if (cmds1[idx].startsWith(cmd1) && cmds2[idx].startsWith(cmd2)) {
                    count++;
                    if (count > 1) {
                        System.out.println("unknown command");
                        break;
                    }
                    res_idx = idx;
                }
            }
            if (count == 0)  System.out.println("unknown command");
            if (count == 1)  System.out.println(operations[res_idx]);
        }
    }
}