code

#include<fstream>
#include<iostream>
#include<cstring>
#include<cstdlib>
using namespace std;



class calender
{
protected:

    public:
        virtual void show()=0;

};

class MONTH:public calender
{
    protected:
        int istartDay,iNumOfDays,mon_num,iyear;
        int month[12]={31,28,31,30,31,30,31,31,30,31,30,31};

    public:

        void get_month()
        {
            cout<<"enter the month\n";
            cin>>mon_num;
            cout<<"enter the startday of the month\n";
            cin>>istartDay;
            mon_num+=1;
        }
        void leap(int iyear)
        {

                if((((iyear%4==0)&&(iyear%100!=0))||(iyear%400==0)))
                {
                    cout<<"LEAP YEAR\n";
                    month[1]=29;
                }
                else{
                    month[1]=28;
                }

            }
        void show()
        {


            mon_num=mon_num-2;
            cout<<"THE MONTH IS:\n";
            switch(mon_num)
            {
                case 0:cout<<"JANUARY\n";
                break;
                case 1:cout<<"FEBRUARY\n";
                break;
                case 2:cout<<"MARCH\n";
                break;
                case 3:cout<<"APRIL\n";
                break;
                case 4:cout<<"MAY\n";
                break;
                case 5:cout<<"JUNE\n";
                break;
                break;
                case 6:cout<<"JULY\n";
                break;
                case 7:cout<<"AUGUST\n";
                break;
                case 8:cout<<"SEPTEMBER\n";
                break;
                case 9:cout<<"OCTOBER\n";
                break;
                case 10:cout<<"NOVEMBER\n";
                break;
                case 11:cout<<"DECEMBER\n";
                break;


            }
            cout<<"\n";
            int i,x;
            iNumOfDays=month[mon_num];
            cout<<"The number of days in the month is:\n"<<iNumOfDays<<endl;

            try{

                            if(istartDay < 0 || istartDay > 6 || iNumOfDays >31 || iNumOfDays <28)
                                throw(x);
                            }catch(int a){
                     cout<<"Invalid input\n";
                     exit(0);
            }


        cout<<"\n";
        cout.width(8);
        cout<<"MON";
        cout.width(8);
        cout<<"TUE";
        cout.width(8);
        cout<<"WED";
        cout.width(8);
        cout<<"THU";
        cout.width(8);
        cout<<"FRI";
        cout.width(8);
        cout<<"SAT";
        cout.width(8);
        cout<<"SUN";
        cout.width(8);
        cout<<"\n";
        for(i=0;i<istartDay;i++)
        cout.width(8);
        cout<<" ";
        i=1;
        while(i<=iNumOfDays)

        {
            cout.width(8);
            cout<<i;
            if(0 == (i+istartDay)%7)
            {
                cout<<"\n";
            }
            i++;
        }

      }

        int& operator[](int x)
        {
            if(x<=0||x>12)
            {

                cout<<"invalid input\n";
                exit(0);
            }
            else
                    return month[x];
        }
};


class LEAP
{
    int leapyear;
    public:
        void check_leap()
        {
            if(leapyear%4==0)
            {
                if(leapyear%100==0)
                {
                   if(leapyear%400==0)
                        cout<<leapyear<<"is a leap year\n";
                else
                    cout<<leapyear<<"is not a leap year\n";

            }
            else
                cout<<leapyear<<"is a leap year\n";
            }
            else
                cout<<"is not a leap year\n";
        }

        void get_input()

        {
             cout<<"Enter the year to check\n";
                cin>>leapyear;
        }
};
class GETDAY: virtual public MONTH
{
    protected:
        int y1,d1,i,r,s;

        char week[7][10];
    public:
        void get_info()
        {
            cout<<"Enter the day, month and year\n";
            cin>>d1>>mon_num>>y1;
        }
        void show()
        {
            s=0;
            strcpy(week[0],"SUNDAY");
            strcpy(week[1],"MONDAY");
            strcpy(week[2],"TUESDAY");
            strcpy(week[3],"WEDNESDAY");
            strcpy(week[4],"THURSDAY");
            strcpy(week[5],"FRIDAY");
            strcpy(week[6],"SATURDAY");

            static int t[]={0,3,2,5,0,3,5,1,4,6,2,4};
            y1-=mon_num<3;
            s=(y1+y1/4-y1/100+y1/400+t[mon_num-1]+d1)%7;
            cout<<"\nTHE DAY IS:\t";
            cout<<week[s]<<endl;
}
};



class NOTE
{
    protected:
     int rday,rmonth,ryear,x;
     string str;
    public:

        void get_date()
        {
            cout<<"enter the date to add a note\n";
                cout<<"dd/mm/yy\n";
                cin>>rday>>rmonth>>ryear;
        }
        void get_string()
        {
            cout<<"enter the string\n";
            cin>>str;
        }
        void add()
        {

        ofstream fout("notes2");
        fout<<str;
        cout<<"Note is added\n";
        fout.close();

        }
         void get_print(NOTE N1)
        {
            try
            {

            if(rday==N1.rday&&rmonth==N1.rmonth&&ryear==N1.ryear)
            {

                ifstream out("notes2");
                out>>str;
                cout<<"\n";
                cout<<"The note added was:\n";
                cout<<str<<"\n";
                out.close();
            }
            else
                throw(x);
        }catch(int i)
        {
            cout<<"no notes to display\n";
        }
        }
};


int main()
{
    while(1)
    {
        calender *ptr1,*ptr2;
         MONTH m;
        ptr1=&m;
        GETDAY g;
        ptr2=&g;
        NOTE N1,N2;
        int value,iyear;
        cout<<"\n**********************************";

        cout<<"\n1.PRINT A MONTH\n2.CHECK FOR A LEAP YEAR\n3.GET THE DAY\n4.ADD NOTE\n5.VIEW NOTE\n6.EXIT\n"<<endl;
        cout<<"\nEnter the operation to be done\n";
        cin>>value;

        switch(value)
        {
            case 1:
                    cout<<"enter the year\n";
                    cin>>iyear;
                     m.get_month();

                    m.leap(iyear);
                    ptr1->show();
                    break;
            case 2:

                    LEAP l;
                    l.get_input();
                    l.check_leap();
                    break;
           case 3:
                    g.get_info();
                    ptr2->show();
                    break;
            case 4: N1.get_date();
                    N1.get_string();
                    N1.add();
                    break;
            case 5:
                    N2.get_date();
                    N2.get_print(N1);
                    break;
            case 6 : exit(0);
        }
    }
return 0;
}