Insert rows based on group ID and difference sum between two datasets - sas

Question

Hello Stack community,
I have a problem where I would appreciate your time and help.
Let's say I have data A with group ID 'A' and the total sum of the group ID 'A' is 11. I have another data B with the same group ID 'A' and the total sum of the group ID 'A' is 20. Now the difference is 9, I want to expand this difference of 9 into 9 rows by that group ID 'A' and /append/insert into data A. I have put the tables for your reference.
data A  
Group Sum
A 1
A 3
A 4
A 1
A 2
Total 11
data b 
Group Sum
A 5
A 2
A 3
A 5
A 5
Total 20
expand the difference of 9 into rows 
Group Count
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1
data want 
Group Sum
A 1
A 3
A 4
A 1
A 2
Total 11
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1
Friends, I really appreciate and thank you for your time and help on this.
I didn't program this yet. I am not sure how to solve this.

Answer 1

This is a strange table format, but given the information you've posted here is a solution that will work for any number of groups. Note that it is not good practice to keep a total row within your data. You can always calculate the total with SQL or PROCs.
First, calculate the differences for all groups:
proc sql;
create table difs as
select a.group, b.total - a.total as dif
from (select group, sum(sum) as total
from a
where group NE 'Total'
group by group
) as a
LEFT JOIN
(select group, sum(sum) as total
from b
where group NE 'Total'
group by group
) as b
ON a.group = b.group
order by group
;
quit;
This creates the following table:
group dif
A 9
Next, we need to add a 1 for every value in the group:
data counts;
set difs;
by group;
do i = 1 to dif;
sum = 1;
output;
end;
drop i dif;
run;
This creates the following table:
group sum
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1
Now we simply append this to the original table to get the desired output:
data want;
set a counts;
run;
Which produces the table we need:
group sum
A 1
A 3
A 4
A 1
A 2
Total 11
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1
A 1