From d7050675b9cac8b62c3ff551b0cfc7e62cdb3ce9 Mon Sep 17 00:00:00 2001 From: Matthew Butterick Date: Tue, 10 Dec 2019 00:23:11 -0800 Subject: [PATCH] notes --- 2019/10.rkt | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/2019/10.rkt b/2019/10.rkt index e47e3af..6bd9979 100644 --- a/2019/10.rkt +++ b/2019/10.rkt @@ -85,14 +85,11 @@ (check-= (radians +16i) (* 1.5 pi) 0.1) ;; 2 -(define (complex->solution c) (+ (* 100 (real-part c)) (imag-part c))) +(define roids-by-dist (sort (remove best-roid roids) < #:key magnitude)) +(define radian-groups (group-by radians roids-by-dist)) +(define radian-groups-by-angle + (sort radian-groups < #:key (compose1 radians car))) (check-eq? - (complex->solution - (car - (list-ref - (sort - (group-by radians (sort (remove best-roid roids) < #:key magnitude)) - < - #:key (λ (i) (radians (car i)))) - 199))) + (match (list-ref radian-groups-by-angle (sub1 200)) + [(cons c _) (+ (* 100 (real-part c)) (imag-part c))]) 502) \ No newline at end of file