10. Program to get the day the month starts on, and the number of days in the month to output a calendar.

// Program to get the day the month starts on, and
//the number of days in the month to output a calendar.

//-------------------Includes--------------------
#include <iostream.h>
#include<conio.h>

//--------------Function Prototypes--------------
int ShowDateLine(int day, int EndDay, int BoxWidth);
void ShowRestOfBox(int BoxWidth, int BoxHeight);
void ShowDates(int BoxWidth);
void Divider(int BoxWidth);

//---------------------Main----------------------
int main()
{
    int StartDay, EndDay, day, counter, weeks;
    const int BoxWidth = 8, BoxHeight = 3;
    char end;
    cout << "1. Sun  2. Mon  3. Tue  4. Wed " << endl;
    cout << "5. Thu  6. Fri  7. Sat" << endl << endl;
    do
    {
        cout << "Enter the starting day: ";
        cin >> StartDay;
        if ((StartDay < 1) || (StartDay > 7))
        {
            cout << "\aError, must be between 1 and 7.\n";
}
    }
    while ((StartDay < 1) || (StartDay > 7)); /* Error checking */
    day = StartDay * -1 + 2;
    cout << "Enter the amount of days in the month: ";
    cin >> EndDay;
    cout << endl;
    weeks = (EndDay + StartDay - 2) / 7;
weeks++;
    //----------------Draw Calendar------------------
    ShowDates(BoxWidth);
    Divider(BoxWidth);
    for (counter = 0; counter < weeks; counter++)
    {
        day = ShowDateLine(day, EndDay, BoxWidth);
        ShowRestOfBox(BoxWidth, BoxHeight);
        Divider(BoxWidth);
    }
    cout<<"Press any key to continue"<<endl;
getch();
}

//------------------Functions--------------------
int ShowDateLine(int day, int EndDay, int BoxWidth)
/* Outputs a '*' then it outputs the days till it reaches the 'EndWeek' value.
If day reaches the EndDay value, then it will output a space instead of a day.
After each date it will output a '*', then proceed 'BoxWidth' spaces ahead. */
{
    int counter, EndWeek;
    cout.setf(ios::right);
    cout << "*";
    EndWeek = day + 7;
    for (counter = 0; counter < 7; counter++, day++)
    {
        cout.width(BoxWidth - 1);
        if ((day < 1) || (day > EndDay))
        {
            cout << " ";
        }
        else
        {
            cout << day;
        }
        cout << "*";
    }
    cout << endl;

    return day;
}
//-----------------------------------------------
void ShowRestOfBox(int BoxWidth, int BoxHeight)
/* Outputs a '*' every 'BoxWidth' length, for a total of 8 '*'.
It does that 'BoxHeight' times. */
{
    int countera, counterb;
    cout.setf(ios::right);
    for (countera = 1; countera < BoxHeight + 0; countera++)
    {
        cout << "*";
        for (counterb = 0; counterb < 7; counterb++)
        {
             cout.width(BoxWidth);
             cout << "*";
        }
        cout << endl;
    }
}
//-----------------------------------------------
void ShowDates(int BoxWidth)
/* Outputs the all 7 days of the week. It takes the 'BoxWidth' and outputs the
day in the
middle of where the box will be. */
{
  cout.setf(ios::right);
  cout.width(BoxWidth / 2 + 2);
  cout << "Sun";
  cout.width(BoxWidth);
  cout << "Mon";
  cout.width(BoxWidth);
  cout << "Tue";
  cout.width(BoxWidth);
  cout << "Wed";
  cout.width(BoxWidth);
  cout << "Thu";
  cout.width(BoxWidth);
  cout << "Fri";
  cout.width(BoxWidth);
  cout << "Sat" << endl;
}
//-----------------------------------------------
void Divider(int BoxWidth)
//Outputs a bar of '*' 'BoxWidth' * 7 + 1
{
    int length, counter;
    length = BoxWidth * 7 + 1;
    for (counter = 0; counter < length; counter++)
    {
        cout << "*";
    }
    cout << endl;
}