include <iostream>

using namespace std;

class lln
{
public:
    int d;
    lln *ad;
}*r;

class ll
{
public:
    ll()
    {
        r = NULL;
    }

    void addbeg(int v);
    void addmiddle(int x, int v);
    void addend(int v);
    void deletebeg();
    int deletev(int x);
    void deleteend();
    int countlist();
    void showlist();
};

void ll::addbeg(int v)
{
    lln *t1 = r;
    lln *t2 = new lln();
    t2->d = v;
    t2->ad = NULL;

    if (r == NULL)
    {
        t1 = r = t2;
    }
    else
    {
        t2->ad = t1;

        r = t2;
    }

    cout<<"\nThe Value "<<v<<" Added."<<endl;
}

void ll::addmiddle(int x, int v)
{
    lln *t1 = r;
    lln *t2 = new lln();
    t2->d = v;
    t2->ad = NULL;

    while (t1->d != x)
    {
        t1 = t1->ad;
    }

    if (t1->ad == NULL)
    {
        t1->ad = t2;
    }
    else
    {
        lln *t3 = t1->ad;

        t1->ad = t2;
        t2->ad = t3;
    }

    cout<<"\nThe Value "<<v<<" Added."<<endl;
}

void ll::addend(int v)
{
    lln *t1 = r;
    lln *t2 = new lln();
    t2->d = v;
    t2->ad = NULL;

    if (r == NULL)
    {
        t1 = r = t2;
    }
    else
    {
        while (t1->ad != NULL)
        {
            t1 = t1->ad;
        }

        t1->ad = t2;
    }

    cout<<"\nThe Value "<<v<<" Added."<<endl;
}

void ll::deletebeg()
{
    lln *t = r;

    r = r->ad;

    cout<<"\nThe Value "<<t->d<<" Deleted."<<endl;

    delete t;
}

int ll::deletev(int x)
{
    int dcu = 0;

    lln *t1 = NULL;
    lln *t2 = r;

    while (t2->ad != NULL)
    {
        if (t2->d != x)
        {
            t1 = t2;
            t2 = t2->ad;
        }
        else if ( (t2 == r) && (t2->d == x) )
        {
            lln *t = r;

            t1 = t2 = r = r->ad;

            delete t;

            dcu++;
        }
        else
        {
            lln *t = t2;

            t2 = t2->ad;
            t1->ad = t2;

            delete t;

            dcu++;
        }
    } if ( (t2->ad == NULL) && (t2->d == x) )
    {
        lln *t = t2;

        t1->ad = NULL;

        t2 = t1;

        delete t;

        dcu++;
    }

    return dcu;
}

void ll::deleteend()
{
    lln *t = NULL;
    lln *t1 = r;

    do
    {
        if (t1->ad != NULL)
        {
            t = t1;
            t1 = t1->ad;
        }
    }
    while (t1->ad != NULL);

    lln *t2 = t1;
    t->ad = NULL;
    t1 = t;

    cout<<"\nThe Value "<<t2->d<<" Deleted."<<endl;

    delete t2;


}

int ll::countlist()
{
    int cun = 0;
    if (r == NULL)
    {
        return 0;
    }
    else
    {
        lln *t = r;

        while (t->ad != NULL)
        {
            cun++;
            t = t->ad;
        }

        cun++;

        return cun;
    }void ll::showlist()
{
    if (r == NULL)
    {
        cout<<"\nList is Empty"<<endl;
    }
    else
    {
        cout<<"\nList Values:-"<<endl;

        lln *t = r;

        while (t->ad != NULL)
        {
            cout<<t->d<<endl;
            t = t->ad;
        }

        cout<<t->d<<endl;
    }
}

int main()
{
    ll *ru = new ll();

    int ch, x, v;

    do
    {
        cout<<"\n1. Add Value at Beginning."<<endl;
        cout<<"2. Add Value at a Position."<<endl;
        cout<<"3. Add Value at End."<<endl;
        cout<<"4. Delete First Value."<<endl;
        cout<<"5. Delete Particular Value."<<endl;
        cout<<"6. Delete Last Value."<<endl;
        cout<<"7. Count Number of Values."<<endl;
        cout<<"8. Show All Values."<<endl;
        cout<<"9. Exit..."<<endl;
        cout<<"Enter Operation No.: ";
        cin>>ch;

        switch(ch)
        {
        case 1:
            {
                cout<<"\nEnter a Value: ";
                cin>>v;
                ru->addbeg(v);
                break;
            }

        case 2:
            {
                cout<<"\nEnter a Value: ";
                cin>>v;

                int cu = ru->countlist();

                if (cu == 0)
                {
                    ru->addbeg(v);
                }
                else
                {
                    ru->showlist();
                    cout<<"Enter The Value to Add After it: ";
                    cin>>x;
                    ru->addmiddle(x, v);
                }
                break;
            }

        case 3:
            {
                cout<<"\nEnter a Value: ";
                cin>>v;
                ru->addend(v);
                break;
            }

        case 4:
            {
                int cu = ru->countlist();

                if (cu == 0)
                {
                    cout<<"\nThe List is Empty"<<endl;
                }
                else
                {
                    ru->deletebeg();
                }
                break;
            }

        case 5:
            {
                int cu = ru->countlist();

                if (cu == 0)
                {
                    cout<<"\nThe List is Empty"<<endl;
                }
                else
                {
                    ru->showlist();
                    cout<<"Enter Value to Delete: ";
                    cin>>x;
                    int dcu = ru->deletev(x);

                    if (dcu == 0)
                    {
                        cout<<"\nThe Value "<<x<<" is NOT on The List."<<endl;
                    }
                    else
                    {
                        cout<<"\nThe Values "<<x<<" Deleted."<<endl;
                    }
                }
                break;
            }

        case 6:
            {
                int cu = ru->countlist();

                if (cu == 0)
                {
                    cout<<"\nThe List is Empty"<<endl;
                }
                else
                {
                    ru->deleteend();
                }
                break;
            }

        case 7:
            {
                int cu = ru->countlist();

                if (cu==0)
                {
                    cout<<"\nThe List is Empty"<<endl;
                }
                else
                {
                    cout<<"\nThe List has "<<cu<<" Value."<<endl;
                }
                break;
            }

        case 8:
            {
                ru->showlist();
                break;
            }

        case 9:
            {
                cout<<"\n..."<<endl;
                break;
            }

        default:
            {
                cout<<"\nInvalid Operation No"<<endl;
                break;
            }
        }
    }
    while(ch != 9);

    return 0;
}