[编程题]配置文件恢复

Talk is cheap, show me the code.

一、问题描述

有6条配置命令，它们执行的结果分别是：

reset reset whatreset board board faultboard add where to addboard delet no board at allreboot backplane impossiblebackplane abort install firsthe he unkown command

注意：he he不是命令。

为了简化输入，方便用户，以“最短唯一匹配原则”匹配：

1、若只输入一字串，则只匹配一个关键字的命令行。例如输入：r，根据该规则，匹配命令reset，执行结果为：reset what；输入：res，根据该规则，匹配命令reset，执行结果为：reset what；

2、若只输入一字串，但本条命令有两个关键字，则匹配失败。例如输入：reb，可以找到命令reboot backpalne，但是该命令有两个关键词，所有匹配失败，执行结果为：unkown command

3、若输入两字串，则先匹配第一关键字，如果有匹配但不唯一，继续匹配第二关键字，如果仍不唯一，匹配失败。例如输入：r b，找到匹配命令reset board，执行结果为：board fault。

4、若输入两字串，则先匹配第一关键字，如果有匹配但不唯一，继续匹配第二关键字，如果唯一，匹配成功。例如输入：b a，无法确定是命令board add还是backplane abort，匹配失败。

5、若输入两字串，第一关键字匹配成功，则匹配第二关键字，若无匹配，失败。例如输入：bo a，确定是命令board add，匹配成功。

6、若匹配失败，打印“unkown command”

输入描述：

多行字符串，每行字符串一条命令

输出描述：

执行结果，每条命令输出一行

输入例子：

resetreset boardboard addboard deletreboot backplanebackplane abort

输出例子：

reset whatboard faultwhere to addno board at allimpossibleinstall first

二、解题思路

纯逻辑题，不过很容易写得很长很繁琐，先给出一个稍长的解法。

代码：

#include <iostream>#include <string>using namespace std;void test1(){    string line;    while(getline(cin, line))    {        if(line.find(" ") != string::npos)        {            string cmd1 = line.substr(0, line.find_first_of(" "));            string cmd2 = line.substr(line.find_first_of(" ")+1);            if(((cmd1 == "r" || cmd1 == "re") && cmd2 == "b") || (cmd1 == "b" && cmd2 == "a"))            {                cout << "unkown command" << endl;                continue;            }            bool flag2 = false;            if(cmd1[0] == 'r')            {                flag2 = true;                string temp = "reset";                int num = 0;                if(temp.find(cmd1) != string::npos)                {                    temp = "board";                    if(cmd2[0] == 'b' && temp.find(cmd2) != string::npos)                    {                        cout << "board fault" << endl;                        num++;                    } else                        cout << "unknown command" << endl;                }                temp = "reboot";                if(temp.find(cmd1) != string::npos)                {                    temp = "backplane";                    if(cmd2[0] == 'b' && temp.find(cmd2) != string::npos)                    {                        cout << "impossible" << endl;                        num++;                    } else                        cout << "unknown command" << endl;                }                if(num != 1)                    cout << "unknown command" << endl;            }            if(cmd1[0] == 'b')            {                flag2 = true;                string temp = "board";                int num = 0;                if(temp.find(cmd1) != string::npos)                {                    bool flag = false;                    temp = "add";                    if(cmd2[0] == 'a' && temp.find(cmd2) != string::npos)                    {                        num++;                        cout << "where to add" << endl;                        flag = true;                    }                    temp = "delet";                    if(cmd2[0] == 'd' && temp.find(cmd2) != string::npos)                    {                        num++;                        cout << "no board at all" << endl;                        flag = true;                    }                    if(!flag)                        cout << "unkown command" << endl;                }                temp = "backplane";                if(temp.find(cmd1) != string::npos)                {                    temp = "abort";                    if(cmd2[0] == 'a' && temp.find(cmd2) != string::npos)                    {                        cout << "install first" << endl;                        num++;                    } else                        cout << "unkown command" << endl;                }                if(num != 1)                    cout << "unkown command" << endl;            }            if(!flag2)                cout << "unkown command" << endl;        } else {            string temp = "reset";            if(line[0] == 'r' && temp.find(line) != string::npos)                cout << "reset what" << endl;            else                cout << "unkown command" << endl;        }    }}int main(){    test1();    return 0;}

再给出一种稍微简短一点的解法：

代码：

#include<iostream>#include<string>#include<vector>#include<algorithm>using namespace std;vector<pair<pair<string, string>, string>> helper{    {{"reset",""},"reset what"},{ {"reset","board"},"board fault" },{ {"board","add"},"where to add" },    { {"board","delet"},"no board at all" }, { {"reboot","backplane"},"impossible" },    { {"backplane","abort"},"install first" } };int main() {        string str;        while (getline(cin,str)) {                int _count = count(str.begin(), str.end(), ' ');                if (_count == 0)                        if (helper[0].first.first.find(str) != string::npos)                                cout << helper[0].second << endl;                        else                 cout << "unkown command" << endl;               else if (_count == 1 && str[str.size() - 1] != ' ') {                        int flag = 0;                        string tmp;                        string part1 = str.substr(0, str.find(' '));                        string part2 = str.substr(str.find(' ') + 1);                        for (auto p : helper) {                                if (p.first.first.find(part1) != string::npos &&                 p.first.second.find(part2) != string::npos) {                                        ++flag;                                        if (flag == 2) break;                                            tmp = p.second;                                }                        }                       if (flag == 1)                 cout << tmp << endl;                        else                 cout<< "unkown command" << endl;                }                else cout << "unkown command" << endl;        }}

补充的测试用例：

输入：

r bre bb a

输出：

unknown commandunknown commandunknown command