data_structures_hw1/prog/IncDate.java

// The IncDate class
// Do not make changes to anything other than the body of increment() method
// Your name here

public class IncDate extends Date
{
    // copy constructor
    public IncDate(Date o)
    {
        super(o.m_month, o.m_day, o.m_year);
    }

    // constructor
    public IncDate(int month, int day, int year)
    {
        super(month, day, year);
    }

    public void addDays(int numDays)
    {
        // TODO: implement this method
        int days_to_add = numDays;
        int[] MONTHS = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        boolean is_leap = (m_year % 400 == 0) || ((m_year % 4 == 0) && !(m_year % 100 == 0));

        for (int current_month = 0; current_month < m_month-1; current_month ++)
            days_to_add += MONTHS[current_month];

        if ((m_month > 2) && is_leap)
            days_to_add += 1;
        days_to_add += m_day-1;
        m_month = 1;
        m_day = 1;
        while (days_to_add > 365) {
            is_leap = (m_year % 400 == 0) || ((m_year % 4 == 0) && !(m_year % 100 == 0));
            if (is_leap)
                days_to_add -= 1;
            days_to_add -= 365;
            m_year += 1;
        }
	is_leap = (m_year % 400 == 0) || ((m_year % 4 == 0) && !(m_year % 100 == 0));
	if (is_leap)
            MONTHS[1] +=1;

        while (days_to_add >= MONTHS[m_month-1]) {
            days_to_add -= MONTHS[m_month-1];
            m_month += 1;
        }
        m_day=days_to_add+1;
    }
}