题解 | #配置文件恢复#

#include <iostream>
#include <sstream>
using namespace std;

class Command {
  private:
    //输入命令
    string command;

    //配置命令
    static const string c1, c2, c3, c4, c5, c6;

  public:
    //构造函数
    Command(const string s);

    //析构函数
    ~Command();

    //匹配命令
    const string matchCommand(void)const;

    //输出结果
    void print(const string s)const;

    //配置文件恢复
    void recovery(void)const;

    //匹配reset
    const bool matchReset(const string s)const;

    //匹配board
    const bool matchBoard(const string s)const;

    //匹配add
    const bool matchAdd(const string s)const;

    //匹配delete
    const bool matchDelete(const string s)const;

    //匹配reboot
    const bool matchReboot(const string s)const;

    //匹配backplane
    const bool matchBackplane(const string s)const;

    //匹配abort
    const bool matchAbort(const string s)const;

    //匹配两个单词
    const string match2(const string s1, const string s2)const;
};

//初始化配置命令
const string Command::c1 = "reset";
const string Command::c2 = "reset board";
const string Command::c3 = "board add";
const string Command::c4 = "board delete";
const string Command::c5 = "reboot backplane";
const string Command::c6 = "backplane abort";

Command::Command(const string s) {
    this->command = s;
    return;
}

Command::~Command() {
}

const string Command::matchCommand(void) const {
    //如果输入的是完整命令，直接返回
    if ((this->command == this->c1) || (this->command == this->c2) ||
            (this->command == this->c3) || (this->command == this->c4) ||
            (this->command == this->c5) || (this->command == this->c6))
        return this->command;

    //输入重定向到字符串
    string s1, s2;
    istringstream iss(this->command);
    iss >> s1 >> s2;

    //如果只有一字串，只有能匹配"reset"时能匹配成功
    if (s2 == "") {
        if (this->matchReset(s1))
            return this->c1;
        else return string();
    }

    //如果输入的是两字串

    //如果输入的是完整命令的一部分，返回完整命令
    if (this->command == this->c2.substr(0, this->command.size()))
        return this->c2;
    if (this->command == this->c3.substr(0, this->command.size()))
        return this->c3;
    if (this->command == this->c4.substr(0, this->command.size()))
        return this->c4;
    if (this->command == this->c5.substr(0, this->command.size()))
        return this->c5;
    if (this->command == this->c6.substr(0, this->command.size()))
        return this->c6;

    //如果输入的两字串分别匹配命令的两个单词且唯一
    return this->match2(s1, s2);
}

void Command::print(const string s) const {
    if (s == this->c1) {
        cout << "reset what" << endl;
        return;
    }
    if (s == this->c2) {
        cout << "board fault" << endl;
        return;
    }
    if (s == this->c3) {
        cout << "where to add" << endl;
        return;
    }
    if (s == this->c4) {
        cout << "no board at all" << endl;
        return;
    }
    if (s == this->c5) {
        cout << "impossible" << endl;
        return;
    }
    if (s == this->c6) {
        cout << "install first" << endl;
        return;
    }
    cout << "unknown command" << endl;
    return;
}

void Command::recovery(void) const {
    this->print(this->matchCommand());
    return;
}

const bool Command::matchReset(const string s) const {
    if (s == this->c1.substr(0, s.size()))
        return true;
    return false;
}

const bool Command::matchBoard(const string s) const {
    if (s == string("board").substr(0, s.size()))
        return true;
    return false;
}

const bool Command::matchAdd(const string s) const {
    if (s == string("add").substr(0, s.size()))
        return true;
    return false;
}

const bool Command::matchDelete(const string s) const {
    if (s == string("delete").substr(0, s.size()))
        return true;
    return false;
}

const bool Command::matchReboot(const string s) const {
    if (s == string("reboot").substr(0, s.size()))
        return true;
    return false;
}

const bool Command::matchBackplane(const string s) const {
    if (s == string("backplane").substr(0, s.size()))
        return true;
    return false;
}

const bool Command::matchAbort(const string s) const {
    if (s == string("abort").substr(0, s.size()))
        return true;
    return false;
}

const string Command::match2(const string s1, const string s2) const {
    //匹配reset board
    if (this->matchReset(s1))
        if (this->matchBoard(s2)) {

            //如果匹配reset board却不匹配reboot backplane
            if (!this->matchReboot(s1))
                return this->c2;
            if (!this->matchBackplane(s2))
                return this->c2;

            //如果匹配reset board和reboot backplane
            return string();
        }

    //匹配board add
    if (this->matchBoard(s1))
        if (this->matchAdd(s2)) {

            //如果匹配board add却不匹配backplane abort
            if (!this->matchBackplane(s1))
                return this->c3;
            if (!this->matchAbort(s2))
                return this->c3;

            //如果匹配board add和backplane abort
            return string();
        }

    //匹配board delete
    if (this->matchBoard(s1))
        if (this->matchDelete(s2))
            return this->c4;

    //匹配reboot backplane却不匹配reset board
    if (this->matchReboot(s1))
        if (this->matchBackplane(s2))
            return this->c5;

    //匹配backplane abort却不匹配board add
    if (this->matchBackplane(s1))
        if (this->matchAbort(s2))
            this->c6;

    //现有配置命令都不匹配
    return string();
}

int main() {
    string a;
    while (getline(cin, a)) { // 注意 while 处理多个 case
        Command(a).recovery();
    }
}
// 64 位输出请用 printf("%lld")