AOCDay2.sql

-- Preprocessing the input into a csv e.g. 1,3,a,abcde

-- Creating table:
CREATE TABLE aoc_2(lower int4, upper int4, letter char, password varchar);

--Part 1:
SELECT
  count(*)
FROM
  aoc_2
WHERE
   (char_length(password) - char_length(replace(password, letter, ''))) <@ int4range(lower,upper, '[]');

-- Part 2:
SELECT
  count(*)
FROM aoc_2
WHERE
  (substring(password, lower,1) = letter)::integer
  + (substring(password,upper,1) = letter)::integer
  = 1;