** store the values for C  in a small array,  then when B =0 put then out; data one; infile cards missover; input A B C; cards; 1 . 1 1 . 2 1 . 3 1 0 . 2 . 1 2 . 2 2 0 . 3 . 1 3 . 2 3 0 . ;;;; run; data two; set one ; by a b; array hold hold1-hold10; retain hold1-hold10 .; if b=. then do; x+1; hold{x}=c; output; end; if b=0 then do; do t=1 to x; c=hold{t}; output; end; end; if last.a then do; do t=1 to x; hold(t)=.; end; x=0; end; drop hold1-hold10 x t; proc print; run;     Obs A B C 1     1 . 1 2     1 . 2 3     1 . 3 4     1 0 1 5     1 0 2 6     1 0 3 7     2 . 1 8     2 . 2 9     2 0 1 10   2 0 2 11   3 . 1 12   3 . 2 13   3 0 1 14   3 0 2   ... View more

Code: Program data have; input A   B   C; cards; 1 . 1 1 . 2  1 . 3 1 0 . 2 . 1 2 . 2 2 0 . 3 . 1 3 . 2 3 0 . ; run; proc sql; create table want as select a.*,b.c   from (select distinct A,B from have) as a,    (select distinct A,C from have where C is not missing) as b    where a.A=b.A    order by a.a,a.b,b.c; quit; ... View more