;;; solver.el --- Day 06 -*- lexical-binding: t; -*-
;;
;; Copyright (C) 2022 Óscar Nájera
;;
;; Author: Óscar Nájera <hi@oscarnajera.com>
;; Maintainer: Óscar Nájera <hi@oscarnajera.com>
;; Created: December 06, 2022
;; Modified: December 06, 2022
;;
;; This file is not part of GNU Emacs.
;;
;;; Commentary:
;;
;;  Day 06
;;
;;; Code:
;;;

(require 'ert)

(defun solver (start-marker-len)
  (with-temp-buffer
    (insert-file-contents-literally "input")
    (goto-char (point-min))
    (cl-loop with acc = (make-ring start-marker-len)
             for chr = (prog1 (char-after) (forward-char))
             do (ring-insert acc chr)
             count chr
             while (< (length (seq-uniq (ring-elements acc) #'eq)) start-marker-len))))

(ert-deftest test-solver ()
  (should (= 1655 (solver 4)))
  (should (= 2665 (solver 14))))