declare	@t table (
	id bigint not null
   ,value decimal(23, 10) not null
   ,r decimal(23, 10) not null 
   ,source_id bigint null
   )

insert into @t(id, value, r, source_id)
select 1, -50, -50, null
union all
select 2, -50, -50, null
union all
select 3, 125, 125, null

select 1, -50, 0, 3
union all
select 2, -50, 0, 3
union all
select 3, 125, 25, null

select 1, -50, -50, null
union all
select 2, -50, -50, null
union all
select 3, 75, 75, null

select 1, -50, 0, 3
union all
select 2, -25, 0, 3
union all
select 3, 75, 0, null
union all
select 4, -25, -25, null

--insert into @t(id, value, r, source_id) select 1, -50, -50, null union all select 2, -50, -50, null union all select 3, 25, 25, null
insert into @t(id, value, r, source_id) select 1, -50, -50, null union all select 2, -50, -50, null union all select 3, 125, 125, null

declare @t_temp table (id bigint null   ,value decimal(23, 10) not null   ,r decimal(23, 10) not null    ,source_id bigint null, old_id bigint null)

while exists(select 1 from @t where r > 0) and exists(select 1 from @t where r < 0)
begin

;with t(id, value, r, source_id, id_old)
as
(
select a.id, a.value, case when a.r+b.r > 0 then 0 else a.r+b.r end, b.id as source_id, null from (select row_number() over(order by id) n1, * from @t where r < 0)a
join (select row_number() over(order by id) n1, * from @t where r > 0)b on a.n1 = b.n1
)
insert into @t_temp(id, value, r, source_id, old_id)
select t1.id, t1.value, t1.r+isnull(t.value, 0) as r, t1.source_id, null from @t t1
left join t on t.source_id = t1.id
where t1.id not in (select id from t)
union all
select id, value, 0 as r, source_id, null from t
union all 
select null as id, t.value-t.r, t.value-t.r, null as source_id, id from t
where t.r <> 0

delete @t

insert into @t(id, value, r, source_id, old_id)
select id, value, r, source_id, old_id from @t_temp

delete @t_temp

end

select * from @t