From 8777ff071f7bb37631baa7b6717ad29961e50911 Mon Sep 17 00:00:00 2001
From: "H.J" <thechairman@thechairman.info>
Date: Wed, 9 Oct 2024 11:36:55 -0400
Subject: sorting by language

---
 aoc2023-racket/day-03/day-03.rkt | 72 ----------------------------------------
 1 file changed, 72 deletions(-)
 delete mode 100644 aoc2023-racket/day-03/day-03.rkt

(limited to 'aoc2023-racket/day-03/day-03.rkt')

diff --git a/aoc2023-racket/day-03/day-03.rkt b/aoc2023-racket/day-03/day-03.rkt
deleted file mode 100644
index 60e81a6..0000000
--- a/aoc2023-racket/day-03/day-03.rkt
+++ /dev/null
@@ -1,72 +0,0 @@
-#lang racket
-
-(require advent-of-code
-         threading)
-
-(struct posn (x y) #:transparent)
-(struct part (n posns) #:transparent)
-
-(define (make-board port)
-  (for*/hash ([(row y) (in-indexed (port->lines port))]
-              [(col x) (in-indexed (string->list row))]
-              #:unless (equal? col #\.))
-    (define v
-      (cond
-        [(string->number (string col))]
-        [(equal? col #\*) 'gear]
-        [else 'other]))
-    (values (posn x y) v)))
-
-(define board (~> (open-aoc-input (find-session) 2023 3 #:cache #true) make-board))
-
-(define (posn<? a b)
-  (match-define (list (cons (posn a-x a-y) _) (cons (posn b-x b-y) _)) (list a b))
-  (if (= a-y b-y) (< a-x b-x) (< a-y b-y)))
-
-(define (find-cells f b)
-  (~> (for/hash ([(k v) (in-hash b)] #:when (f v))
-        (values k v))
-      hash->list
-      (sort posn<?)))
-
-(define (group-into-parts cells [acc '()])
-  (match* (cells acc)
-    [('() acc)
-     acc]
-    [((list* (cons (and pt (posn x y)) n) cs)
-      (list* (part n* (and pts (list* (posn x* y) rest-pts)))
-             rest-acc))
-     #:when (= (- x x*) 1)
-     (group-into-parts cs (cons (part (+ n (* n* 10)) (cons pt pts)) rest-acc))]
-    [((list* (cons pt n) cs) acc)
-     (group-into-parts cs (cons (part n (list pt)) acc))]))
-
-(define (neighbors p)
-  (for*/list ([dx '(-1 0 1)]
-              [dy '(-1 0 1)]
-              #:unless (and (= dx 0) (= dy 0)))
-    (posn (+ dx (posn-x p)) (+ dy (posn-y p)))))
-
-(define to-neighbors (λ~>> part-posns (append-map neighbors) remove-duplicates))
-(define (symbol-in-neighbors b pt acc)
-  (~>> pt
-       to-neighbors
-       (ormap (λ (p) (let ([lookup (hash-ref b p #f)])
-                       (or (equal? lookup 'gear) (equal? lookup 'other)))))
-       ((λ (bool) (if bool (+ acc (part-n pt)) acc)))))
-
-;; part 1
-(define parts (~>> board (find-cells integer?) group-into-parts))
-(foldl (curry symbol-in-neighbors board) 0 parts)
-
-;; part 2
-(define gears (~>> board (find-cells (curry equal? 'gear)) (map car)))
-(define parts-with-neighbors (map (λ (pt) (struct-copy part pt [posns (to-neighbors pt)])) parts))
-
-(define (find-parts-near-gear pts gear)
-  (filter-map (λ (pt) (and (findf (curry equal? gear) (part-posns pt)) (part-n pt))) pts))
-
-(~>> gears
-     (filter-map (λ~>> (find-parts-near-gear parts-with-neighbors)
-                       ((λ (ns) (if (= (length ns) 2) (* (first ns) (second ns)) #f)))))
-     (apply +))
-- 
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