1 files changed, 0 insertions, 59 deletions
diff --git a/2021/day-21/day-21.rkt b/2021/day-21/day-21.rkt
deleted file mode 100644
index 9ca9b1b..0000000
--- a/2021/day-21/day-21.rkt
+++ /dev/null
@@ -1,59 +0,0 @@
-#lang racket
-(require threading
-         memoize)
-
-;; not going to bother importing the data since it's just two lines of text
-(define player-1-start 4)
-(define player-2-start 6)
-
-(define track (sequence->stream (in-cycle (inclusive-range 1 10))))
-(define current-turn (in-cycle (list 'player-1 'player-2)))
-(define die-rolls (sequence->stream (in-cycle (inclusive-range 1 100))))
-
-;; part 1
-(~> (for/fold ([player-1-score 0]
-               [player-1-track (stream-tail track (sub1 player-1-start))]
-               [player-2-score 0]
-               [player-2-track (stream-tail track (sub1 player-2-start))]
-               [dice die-rolls]
-               [last-turn 0]
-               #:result (list (min player-1-score player-2-score) (* 3 last-turn)))
-              ([turn-count (in-naturals 1)]
-               [turn-for current-turn]
-               #:break (or (player-1-score . >= . 1000) (player-2-score . >= . 1000)))
-      (define rolls (apply + (stream->list (stream-take dice 3))))
-      (match turn-for
-        ['player-1
-         (define next-track (stream-tail player-1-track rolls))
-         (values (+ player-1-score (stream-first next-track))
-                 next-track
-                 player-2-score
-                 player-2-track
-                 (stream-tail dice 3)
-                 turn-count)]
-        ['player-2
-         (define next-track (stream-tail player-2-track rolls))
-         (values player-1-score
-                 player-1-track
-                 (+ player-2-score (stream-first next-track))
-                 next-track
-                 (stream-tail dice 3)
-                 turn-count)]))
-    (apply * _))
-
-;; part 2
-(define d3 (list 1 2 3))
-(define roll-space (~>> (cartesian-product d3 d3 d3) (map (λ~>> (apply +)))))
-
-(define/memo
- (next-turns p1-score p2-score p1-start p2-start)
- (cond
-   [(p1-score . >= . 21) '(1 0)]
-   [(p2-score . >= . 21) '(0 1)]
-   [else
-    (for/fold ([wins '(0 0)]) ([roll (in-list roll-space)])
-      (define move-to (add1 (modulo (sub1 (+ roll p1-start)) 10)))
-      (define possible-wins (next-turns p2-score (+ p1-score move-to) p2-start move-to))
-      (list (+ (first wins) (second possible-wins)) (+ (second wins) (first possible-wins))))]))
-
-(~>> (next-turns 0 0 player-1-start player-2-start) (apply max))