public class AppointmentBook
{
    private boolean[9][60] freePeriod = new boolean[9][60];

    public AppointmentBook()
    {
	for (int i = 0; i < 8; i++)
	    for (int j = 0; j < 60; j++)
		freePeriod[i][j] = true;        
    }

    /**
     * Returns true if minute in period is available for an appointment and 
     * returns false otherwise
     * Preconditions: 1 <= period <= 8; 0 <= minute <= 59
     */
    private boolean isMinuteFree( int period, int minute )
    {
        return freePeriod[period][minite];
    }
    
    /**
     * Marks the block of minutes that starts at startMinute in period and
     * is duration minutes long as reserved for an appointment
     * Preconditions: 1 <= period <= 8; 0 <= startMinute <= 59;
     * 1 <= duration <= 60
     */
    private void reserveBlock( int period, int startMinute, int duration )
    {
	for ( int j = startMinute; j < startMinute+duration; j++)
	    freePeriod[period][j] = false;
    }
    
    /**
     * Searches for the first block of duration free minutes during period, 
     * as described in part (a). 
     * Returns the first minute in the block if such a block is found or 
     * returns -1 if no such block is found.
     * Preconditions: 1 <= period <= 8; 1 <= duration <= 60
     */
    public int findFreeBlock( int period, int duration )
    {   
        /* to be implemented in part (a) */ 

        return -1;   // Change when writing answer
    }
    
    /**
     * Searches periods from startPeriod to endPeriod, inclusive, for a block
     * of duration free minutes, as described in part (b). 
     * If such a block is found, calls reserveBlock to reserve the block 
     * of minutes and returns true; otherwise returns false.
     * Preconditions: 1 <= startPeriod <= endPeriod <= 8; 1 <= duration <= 60
     */
    public boolean makeAppointment(int startPeriod, int endPeriod, int duration)
    {
	/* to be implemented in part (b) */

        return false;  // Change when writing answer
    }
}