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day07: make a bit more idiomatic (i think)

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This commit is contained in:
Sijmen Schoon 2021-12-09 13:55:14 +01:00
parent d4aba82554
commit 299ccb33d0
Signed by: vijfhoek
GPG key ID: DAF7821E067D9C48
1 changed files with 16 additions and 22 deletions
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38
day07.scm
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@ -7,31 +7,25 @@
(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))
(let* ((sorted (sort numbers <))
(median (list-ref sorted (floor/ (length numbers) 2)))
(part1
(foldl (lambda (x y) (+ x (abs (- y median))))
0
numbers)))
(format #t "part 1: ~A~%" part1))
; PART 2
(define (triangular n) (/ (* n (+ n 1)) 2))
(define (part2- avg)
(foldl
(lambda (x y) (+ x (triangular (abs (- y avg)))))
0
numbers))
(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))
(let* ((len (length numbers))
(sum (foldl + 0 numbers))
(avg-ceil (ceiling/ sum len))
(avg-floor (floor/ sum len))
(part2 (min (part2- avg-ceil) (part2- avg-floor))))
(format #t "part 2: ~A~%" part2))