// Introduction to Software Testing
// Authors: Paul Ammann & Jeff Offutt
// Chapter 3, section 3.4, page 132




class cal
{

public static int cal (int month1, int day1, int month2,
                       int day2, int year)
{
//***********************************************************
// Calculate the number of Days between the two given days in
// the same year.
// preconditions : day1 and day2 must be in same year
//               1 <= month1, month2 <= 12
//               1 <= day1, day2 <= 31
//               month1 <= month2
//               The range for year: 1 ... 10000
//***********************************************************
   int numDays = 0; 
  
   if (month2 == month1) // in the same month
      numDays  = day2 - day1;
   else
   { 
      // Skip month 0.
      int daysIn[] = {0, 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
      // Are we in a leap year?
      int m4 = year % 4; 
      int m100 = year % 100;
      int m400 = year % 400;
      if ((m4 != 0) || ((m100 == 0) && (m400 != 0)))
         daysIn[2] = 28; 
      else
         daysIn[2] = 29;

      // start with days in the two months
      numDays = day2 + (daysIn[month1] - day1);

      // add the days in the intervening months
      for (int i = month1 + 1; i <= month2-1; i++)
         numDays = daysIn[i] + numDays;
   }
   return (numDays);
}

}