(in-package #:adventofcode2020)

(defun simple-fuel (mass)
  (- (floor (/ mass 3))
     2))

(defun complex-fuel (mass)
  (loop with m = (simple-fuel mass)
        while (> m 0) sum m
        do (setf m (simple-fuel m))))

(day 00 input
  (let ((modules (int-list-from input)))
    (part1 (reduce #'+ (mapcar #'simple-fuel modules)))
    (part2 (reduce #'+ (mapcar #'complex-fuel modules)))))

(def-suite day00)
(in-suite day00)

(test simple-fuel
  (is (equal
        '(2 2 654 33583)
        (mapcar #'simple-fuel '(12 14 1969 100756)))))

(test complex-fuel
  (is (equal
        '(2 966 50346)
        (mapcar #'complex-fuel '(14 1969 100756)))))

(run! 'day00)