Advent of Code

aoc1-1.scm

(import chicken scheme)
(use utils)

(define *input* (read-all (current-input-port)))

(define (main)
  (let loop ((input (string->list *input*))
             (i 1))
    (cond ((null? input) i)
          (else (case (car input)
                  ((#\() (loop (cdr input) (+ i 1)))
                  ((#\)) (loop (cdr input) (- i 1))))))))

(print (main))

aoc1-2.scm

(import chicken scheme)
(use utils)

(define *input* (read-all (current-input-port)))

(define (main)
  (let loop ((input (string->list *input*))
             (index 1)
             (flor 0))
    (cond ((null? input) 0)
          ((eq? flor -1) (- index 1))
          (else (case (car input)
                  ((#\() (loop (cdr input) (+ index 1) (+ flor 1)))
                  ((#\)) (loop (cdr input) (+ index 1) (- flor 1))))))))

(print (main))

aoc2-1.scm

(import chicken scheme)
(use utils srfi-1)

(define *input* (read-all (current-input-port)))

(define (gifts-from-input input)
  (string-split (string-trim-right input #\newline) "\n" #t))

(define (gift-parse gift)
  (string-split gift "x"))

(define (gift-total l w h)
  (let ((side1 (* l w))
        (side2 (* w h))
        (side3 (* h l)))
    (+ (* side1 2) (* side2 2) (* side3 2) (min side1 (min side2 side3)))))

(define (gift-total* gift)
  (gift-total
    (string->number (first gift))
    (string->number (second gift))
    (string->number (third gift))))

(define (gift-list-total gifts)
  (apply + (map gift-total* gifts)))

(define (main)
  (print (gift-list-total (map gift-parse (gifts-from-input *input*)))))

(main)

aoc2-2.scm

(import chicken scheme)
(use utils srfi-1)

(define *input* (read-all (current-input-port)))

(define (gifts-from-input input)
  (string-split (string-trim-right input #\newline) "\n" #t))

(define (gift-parse gift)
  (string-split gift "x"))

(define (gift-total l w h)
  (let* ((sides (sort (list l w h) <))
         (x (first sides))
         (y (second sides)))
    (+ x x y y (* l w h))))

(define (gift-total* gift)
  (gift-total
    (string->number (first gift))
    (string->number (second gift))
    (string->number (third gift))))

(define (gift-list-total gifts)
  (apply + (map gift-total* gifts)))

(define (main)
  (print (gift-list-total (map gift-parse (gifts-from-input *input*)))))

(main)