select r.c_plan,
  coalesce(t.c_date, add_months(to_date('20131001', 'RRRRMMDD'), r.run_id - 1)) c_date,
  r.run_id c_tran_id,
  coalesce(t.c_amount, 0) c_amount,
  case
    when t.c_tran_id is not null then 0
    when not exists (
      select *
      from tmp_test t1
      where t1.c_plan = r.c_plan
        and t1.c_tran_id < r.run_id
    ) then 2
    else 1
  end flag
from (
    select *
    from (
        select distinct c_plan from tmp_test
      )
      cross join tmp_run
  ) r
  left join tmp_test t on t.c_tran_id = r.run_id and t.c_plan = r.c_plan
order by r.c_plan, r.run_id
;

| A | 2013-10-01 |  1 | 10 | 0 |
| A | 2013-11-01 |  2 | 10 | 0 |
| A | 2013-12-01 |  3 | 10 | 0 |
| A | 2014-01-01 |  4 | 10 | 0 |
| A | 2014-02-01 |  5 | 10 | 0 |
| A | 2014-03-01 |  6 | 10 | 0 |
| A | 2014-04-01 |  7 | 10 | 0 |
| A | 2014-05-01 |  8 | 10 | 0 |
| A | 2014-06-01 |  9 | 10 | 0 |
| A | 2014-07-01 | 10 | 10 | 0 |
| A | 2014-08-01 | 11 | 10 | 0 |
| A | 2014-09-01 | 12 | 10 | 0 |
| B | 2013-10-01 |  1 |  0 | 2 |
| B | 2013-11-01 |  2 |  0 | 2 |
| B | 2013-12-01 |  3 |  0 | 2 |
| B | 2014-01-01 |  4 | 10 | 0 |
| B | 2014-02-01 |  5 | 10 | 0 |
| B | 2014-03-01 |  6 | 10 | 0 |
| B | 2014-04-01 |  7 |  0 | 1 |
| B | 2014-05-01 |  8 |  0 | 1 |
| B | 2014-06-01 |  9 | 10 | 0 |
| B | 2014-07-01 | 10 | 10 | 0 |
| B | 2014-08-01 | 11 | 10 | 0 |
| B | 2014-09-01 | 12 |  0 | 1 |