Difference between data in two lines II

Hello guys,
I had a question yesterday that I thought I had a perfect answere for. Well I got the perfect answere considering the information I gave the experts but I found one more problem with my code.

Here is the question from yesterday : http://www.experts-exchange.com/Programming/Languages/SQL_Syntax/Q_23471738.html#a21768768

The code i'm using is the last one Sdstuber posted:

SELECT date_val,
          CASE
              WHEN   next_time
                   - time_val >= 1
                  THEN    TO_CHAR (FLOOR (  next_time
                                          - time_val))
                       || ' '
              ELSE NULL
          END
       || TO_CHAR (  TRUNC (SYSDATE)
                   + (  next_time
                      - time_val), 'hh24:mi') time_diff
  FROM (SELECT COST, date_val, time_val,
               LEAD (time_val, 1) OVER (ORDER BY time_val) next_time
          FROM your_table)
 WHERE COST = 0;

Now, my problem is that there is one additional column called TYPE that takes values 1 ,2 or 3.
So my data table is like this

Cost----------Date_val ----------------Time_val------------TYPE

The code above compares two values of Time_val if the first line has a Cost = 0, but I need it to compare values of Time_val between a line with Cost = 0 and the next line with the same TYPE number.
Thanks in advance.