#include <iostream>
#include <list>
#include <string>
#include <cassert>
#include <cmath>
#define STUDENTS 3


using namespace std;
    class Hash
    {
        int BUCKET;
        list<string>* table;

        public :
            Hash(int V);
            void insertItem (string x);
            void deleteItem (string key);


            int hashFunction(const std::string &str)
                {
                    int hash = 0;
                    for (auto &c: str) hash += c;
                    return hash;
                }


            void displayHash();

    };
    Hash::Hash(int b)
    {
        this->BUCKET = b;
        table = new list<string>[BUCKET];
    }
    void Hash::insertItem(std::string key)
    {

       int index = hashFunction(key);
        table[index].push_back(key);
    }
    void Hash::deleteItem(std::string key)
    {
        int index = hashFunction(key);
        list<string> :: iterator i;
        for (i = table[index].begin();i!=table[index].end();i++)
        {
            if(*i == key)
            {
                break;
            }

        }
        if (i != table[index].end())
        {
            table[index].erase(i);
        }
     }
        void Hash::displayHash()
        {
            for (int i =0; i < BUCKET;i++)
            {
                cout << i;
                for (auto x: table[i])
                {
                    cout << "----->" << x;

                }
                cout << endl;
            }
        }
        int main ()
        {
        Hash h(STUDENTS);
            for (int i =0;i<STUDENTS;i++)
            {
                cout << "1.Add new student: " << endl;
                cout << "2.Delete student " << endl;
                cout << "3.Show hash-table " << endl;
                int switcher;
                cin >> switcher;
                switch(switcher)
                {
                case 1:
                    {
                    cin.ignore();
                    cout << "Enter a value: " << endl;

                    string value;
                    getline(std::cin,value);

                    h.insertItem(value);
                    break;
                    }

                    case 2:
                    {
                    cin.ignore();
                        cout << "Enter a value: " << endl;

                        string value;
                        getline(std::cin,value);
                        h.deleteItem(value);
                        break;
                    }
                    case 3:
                    {
                        h.displayHash();
                        break;
                    }
                }
            }
        }