And you could use a format to do a fast position lookup in the array.
You can create kind of a vlookup table with the data step and load the letter to position table into a format. AA=1 AB=2... Z=51.
You could build a temporary array full of zero to intialize the FIRST row, or you can do it the lazy way and build a single row table with zero values.
*Generate variable list pcat_AA--pcat_AZ pcat_B-pcat_Z
and a DATA set with with positional lookup values AA=1 AB=2..... Z=51;
data list ;
length name $ 500 start $ 2;
retain fmtname '$findit';
do i =65 to 90 ;
letter= input( put( i, hex2.), $hex2.);
name=catx(' ', name, cats('pcat_A', letter));
n+1;
start=cats('A',letter);
label=put(n,2.);
output;
end;
do i =66 to 90 ;
letter= input(put( i, hex2.), $hex2.);
name=catx(' ',name, cats('pcat_', letter));
n+1;
start=cats(letter);
label=put(n,2.);
output;
end;
put name=;
call symputx('name_order',name);
drop i name letter;
run;
proc format cntlin=list fmtlib;
select $findit;
run;
*Generate a row of zeros;
data row0;
array cvar{51} &name_order (51*0);
output;
run;
data temp2;
set item;
by cust_edp_id;
if substr(curr_cat,1,1) = 'A' then prod_cat =substr(curr_cat,1,2);
else prod_cat=substr(curr_cat,1,1);
length all_cats $ 300; *may contain duplicates;
all_cats=catx('-',all_Cats,prod_Cat); retain all_cats;
if 0 then set row0; *sets the variable order;
array pc{*} &name_order;
if first.cust_edp_id=1 then do;
_row=1;
set row0 point=_row; *initialize to zero;
end;
_pos=input( put(prod_cat,$findit.), 2.) ;
pc{_pos}=1;
if last.cust_edp_id=1 then do;
output;
all_cats=' ';
end;
*drop curr_cat prod_cat;
drop _pos;
run;
