#include <iostream>

#include <vector>

#include <string>

using namespace std;



typedef struct __Record{

    string key;

    string value;

}Record;

class Dic{

    public:

    bool insert(string,string);

    bool del(string);

    bool has_key(string);

    string get(string);

    int size();

    void clear();

    private:

    vector<Record> vec_0;



};

bool Dic::insert(string key,string value){

    Record rec;



    if(has_key(key)){

        cout<<"Error!Duplicate key!Insert failed!"<<endl;

        return false;

    }

    rec.key = key;

    rec.value = value;

    vec_0.push_back(rec);

    return true;

}

bool Dic::del(string key){

    if(!has_key(key)){

        cout<<"Error!No such key!Delete failed!"<<endl;

        return false;

    }

    for(vector<Record>::iterator it = vec_0.begin(); it != vec_0.end();){

        if(!it->key.compare(key)){

            it = vec_0.erase(it); 

        }else{

            it++;

        }

    }

}

bool Dic::has_key(string key){

    bool res = false;

    for(vector<Record>::iterator it = vec_0.begin(); it != vec_0.end();it++){

        if(!it->key.compare(key)){

            res = true;

        }

    }   

    return res; 

}

string Dic::get(string key){

    string res;

    for(vector<Record>::iterator it = vec_0.begin(); it != vec_0.end();it++){

        if(!it->key.compare(key)){

            res = it->value;

        }

    }

    return res;

}

int Dic::size(){

    return vec_0.size();

}

void Dic::clear(){

    vec_0.clear();

}

int main(){

    Dic dic_0;  

    dic_0.insert("a","used before a noun to refer to a single thing or person that has not been mentioned before, especially when you are not referring to a particular thing or person");

    dic_0.insert("b","John Winston Lennon (b. 9 October 1940, Liverpool, d. 8 December 1980, New York)");

    dic_0.insert("c","an object-oriented version of C (= a computer programming language)");

    dic_0.insert("c","aeee33a");

    cout<<"a:"<<dic_0.get("a")<<endl;

    cout<<"c:"<<dic_0.get("c")<<endl;

    cout<<"b:"<<dic_0.get("b")<<endl;

    cout<<dic_0.get("b111")<<endl;

    dic_0.del("q");

    cout<<"the dictionary size is "<<dic_0.size()<<endl;

    dic_0.clear();

    cout<<"the dictionary size is "<<dic_0.size()<<endl;



    return 0;

}