From 527bc4762f9c66c9244f0ac1fbee6357478ac9ef Mon Sep 17 00:00:00 2001 From: HJ Date: Thu, 9 Dec 2021 18:05:04 -0500 Subject: putting all my solutions together in 1 repository --- 2021/day-07/day-07.rkt | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 2021/day-07/day-07.rkt (limited to '2021/day-07/day-07.rkt') diff --git a/2021/day-07/day-07.rkt b/2021/day-07/day-07.rkt new file mode 100644 index 0000000..81a2e4f --- /dev/null +++ b/2021/day-07/day-07.rkt @@ -0,0 +1,30 @@ +#lang racket +(require advent-of-code + threading + math/statistics) + +(define crab-data + (~> (open-aoc-input (find-session) 2021 7 #:cache #t) + port->string + string-trim + (string-split ",") + (map string->number _))) + +(define (gauss-sum n) (/ (* n (+ n 1)) 2)) +(define (compute-fuel-use f crabs align-to) + (for/sum ([crab (in-list crabs)]) + (f (abs (- crab align-to))))) + +;; using the fact that the optimum location is at the median +;; of the crabs' starting location for the linear relationship +;; and at a coordinate within 1 unit of the mean for the quadratic one + +(~>> crab-data + (median <) + (compute-fuel-use identity crab-data)) + +(~>> crab-data + mean + ((λ (m) (list (floor m) (ceiling m)))) + (map (curry compute-fuel-use gauss-sum crab-data)) + (apply min)) \ No newline at end of file -- cgit v1.2.3