题解 | #配置文件恢复#

import java.util.Scanner;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;

// 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) {
        Map<String, String> comendMap = new HashMap<>();
        comendMap.put("noMatch", "unknown command");
        comendMap.put("backplane abort", "install first");
        comendMap.put("reboot backplane", "impossible");
        comendMap.put("board delete", "no board at all");
        comendMap.put("board add", "where to add");
        comendMap.put("reset board", "board fault");
        comendMap.put("reset", "reset what");
        List<String> listKey = new ArrayList<>();
        for(String temp : comendMap.keySet()) {
            listKey.add(temp);
        }
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            String a = in.nextLine();
            String result = function(a, listKey);
            System.out.println(comendMap.get(result));
        }
    }
    public static String function(String str, List<String> list) {
        String[] cmd = str.split(" ");
        if (cmd.length  == 0 || cmd.length > 2) {
            return "noMatch";
        }
        if (cmd.length == 1 && "reset".startsWith(cmd[0])) {
           return "reset";            
        }
        int count = 0;
        int index = 0;
        for (int i = 0; i < list.size(); i++) {
            String[] tempKey = list.get(i).split(" ");
            if (tempKey.length == 1 || cmd.length == 1) {
                continue;
            }
            if (tempKey[0].startsWith(cmd[0]) && tempKey[1].startsWith(cmd[1])) {
                count++;
                index = i;
            }
        }
        return count != 1 ? "noMatch" : list.get(index);
    }
}