41 lines
884 B
Scheme
41 lines
884 B
Scheme
(import (chicken string))
|
|
(import (chicken format))
|
|
(import (chicken io))
|
|
(import (chicken sort))
|
|
(import (only traversal enumerate))
|
|
(import srfi-1)
|
|
(import srfi-14)
|
|
(import srfi-60)
|
|
(import srfi-141)
|
|
|
|
(define numbers (map string->number (string-split (read-line) ",")))
|
|
|
|
; PART 1
|
|
(define sorted (sort numbers <))
|
|
(define median (list-ref sorted (floor/ (length numbers) 2)))
|
|
|
|
(define (part1)
|
|
(foldl
|
|
(lambda (x y) (+ x (abs (- y median))))
|
|
0
|
|
numbers))
|
|
|
|
|
|
; PART 2
|
|
(define (triangular n) (/ (* n (+ n 1)) 2))
|
|
|
|
(define (part2- avg)
|
|
(foldl
|
|
(lambda (x y) (+ x (triangular (abs (- y avg)))))
|
|
0
|
|
numbers))
|
|
|
|
(define avgCeil (ceiling/ (foldl + 0 numbers) (length numbers)))
|
|
(define avgFloor (floor/ (foldl + 0 numbers) (length numbers)))
|
|
|
|
(define (part2)
|
|
(min (part2- avgCeil) (part2- avgFloor)))
|
|
|
|
|
|
(format #t "part 1: ~A~%" (part1))
|
|
(format #t "part 2: ~A~%" (part2))
|