//
// Program to test "date_convert" function (alternative version).
//

#include <iostream.h>
#include <stdlib.h>

// "error_exit" function.
// Post:  "Bad input" printed; program exited.
// (Yes, this is extremely crude.)
void error_exit(void)
{
  cout << "Bad input\n";
  exit(EXIT_FAILURE);
}

// "print_date" function.
// Pre:  "d", "m", "y" represent a date (day, month, year).
// Post:  Prints the date, in month/day/year form.
void print_date(int d, int m, int y)
{
  cout << "date in month/day/year format:  "
       << m << "/" << d << "/" << y << endl;
  return;
}

// "date_convert" function.
// Pre:  "day" and "year" represent a date, where "day" ranges from
//         1 to 365 (366 for leap years).
// Post:  Prints the date, in month/day/year form.
void date_convert(int day, int year)
{
  // check year for acceptable value.
  if (year < 1) error_exit();

  int days_in_feb;
  // calculate days days in February.
  if ( ((year % 400) == 0) || 
       (((year % 4) == 0) && ((year % 100) != 0)))
      days_in_feb = 29;
  else
      days_in_feb = 28;

  // check day for acceptable value (too small -- check for too big 
  //   later).
  if (day < 1) error_exit();

  int month = 1;		// "initial guess" of January
  int day_in_month = day;

  // calculate month and day_in_month:
  // go through months, one at a time, until we find the one for
  //   this day.
  // January?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess February.
  month = 2;
  day_in_month = day_in_month - 31;
  // February?
  if (day_in_month <= days_in_feb) 
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess March.
  month = 3;
  day_in_month = day_in_month - days_in_feb;
  // March?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess April.
  month = 4;
  day_in_month = day_in_month - 31;
  // April?
  if (day_in_month <= 30)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess May.
  month = 5;
  day_in_month = day_in_month - 30;
  // May?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess June.
  month = 6;
  day_in_month = day_in_month - 31;
  // June?
  if (day_in_month <= 30)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess July.
  month = 7;
  day_in_month = day_in_month - 30;
  // July?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess August.
  month = 8;
  day_in_month = day_in_month - 31;
  // August?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess September.
  month = 9;
  day_in_month = day_in_month - 31;
  // September?
  if (day_in_month <= 30)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess October.
  month = 10;
  day_in_month = day_in_month -	30;
  // October?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess November.
  month = 11;
  day_in_month = day_in_month - 31;
 // November?
 if (day_in_month <= 30)
    {
      print_date(day_in_month, month, year);
      return;
    }
  // no, guess December.
  month = 12;
  day_in_month = day_in_month - 30;
  // December?
  if (day_in_month <= 31)
    {
      print_date(day_in_month, month, year);
      return;
    }
 // none of the above -- error!
 error_exit();
}

int main(void)
{
  int d, y;
  cout << "Enter integers for day (1 to days in year), year:\n";
  cin >> d >> y;
  date_convert(d, y);
  return EXIT_SUCCESS;
}