Your answer inspired me to try using SQLite. :-)

create table input (line);
.import 1.txt input
create table left as select substr(line, 0, 6) as l from input order by l;
create table right as select substr(line, -5) as r from input order by r;
select sum(abs(l-r)) from left join right on left.rowid = right.rowid;
select sum(score) from (select r*count(r) as score from right where r in left group by r);