3 files changed, 111 insertions, 1 deletions
diff --git a/aoc2023-other/day-06/day-06.rkt b/aoc2023-other/day-06/day-06.rkt
index 2897821..399c131 100644
--- a/aoc2023-other/day-06/day-06.rkt
+++ b/aoc2023-other/day-06/day-06.rkt
@@ -1,7 +1,8 @@
 #lang racket
 
 (require advent-of-code
-         threading)
+         threading
+         )
 
 (match-define (list times distances)
   (~> (open-aoc-input (find-session) 2023 6 #:cache #true) port->lines))
diff --git a/aoc2023-other/day-07/day-07.rkt b/aoc2023-other/day-07/day-07.rkt
new file mode 100644
index 0000000..f0a40ea
--- /dev/null
+++ b/aoc2023-other/day-07/day-07.rkt
@@ -0,0 +1,77 @@
+#lang racket
+
+(require advent-of-code
+         threading
+         memo)
+
+(struct hand (cards wager) #:transparent)
+
+(define/match (card->int card)
+  [((? char-numeric?)) (~> card string string->number)]
+  [(#\A) 14]
+  [(#\K) 13]
+  [(#\Q) 12]
+  [(#\J) 11]
+  [(#\T) 10]
+  [(#\*) 1])
+
+(define (parse-hand str #:jokers [jokers? #f])
+  (match-define (list card-str wager-str) (string-split str))
+  (define cards
+    (~> card-str
+        ((λ (str) (if jokers? (string-replace str "J" "*") str)))
+        string->list
+        (map card->int _)))
+  (define wager (~> wager-str string->number))
+  (hand cards wager))
+
+(define input (~> (open-aoc-input (find-session) 2023 7 #:cache #true) port->lines))
+
+(define/memoize (identify-hand h)
+                (define freqs (~> h hand-cards (sort <) (group-by identity _) (map length _)))
+                (match freqs
+                  [(list-no-order 5) 8]
+                  [(list-no-order 1 4) 7]
+                  [(list-no-order 2 3) 6]
+                  [(list-no-order 1 1 3) 5]
+                  [(list-no-order 1 2 2) 4]
+                  [(list-no-order 1 1 1 2) 3]
+                  [(list-no-order 1 1 1 1 1) 2]
+                  [_ 1]))
+
+(define (compare-first-card cs1 cs2)
+  (if (= (first cs1) (first cs2))
+      (compare-first-card (rest cs1) (rest cs2))
+      (< (first cs1) (first cs2))))
+
+(define (compare-hands with h1 h2)
+  (define rank1 (with h1))
+  (define rank2 (with h2))
+  (if (= rank1 rank2) (compare-first-card (hand-cards h1) (hand-cards h2)) (< rank1 rank2)))
+
+;; part 1
+
+(define (compare-hands-no-wilds h1 h2)
+  (compare-hands identify-hand h1 h2))
+
+(define (total-score in #:jokers [jokers? #false])
+  (for/sum ([(h i)
+             (in-indexed (~> in
+                             (map (curry parse-hand #:jokers jokers?) _)
+                             (sort (if jokers? compare-hands-no-wilds compare-hands-with-wilds))))])
+           (* (add1 i) (hand-wager h))))
+
+(total-score input)
+
+;; part 2
+
+(define/memoize (find-best-joker-substitution h)
+                (for/fold ([best-hand (hand '() 0)]) ([wild (in-inclusive-range 2 14)])
+                  (define trial-hand
+                    (hand (map (λ (c) (if (= c 1) wild c)) (hand-cards h)) (hand-wager h)))
+                  (if (> (identify-hand trial-hand) (identify-hand best-hand)) trial-hand best-hand)))
+
+(define (compare-hands-with-wilds h1 h2)
+  (compare-hands (λ~> find-best-joker-substitution identify-hand) h1 h2))
+
+(total-score input #:jokers #true)
diff --git a/aoc2023-other/day-08/day-08.rkt b/aoc2023-other/day-08/day-08.rkt
new file mode 100644
index 0000000..bc234b5
--- /dev/null
+++ b/aoc2023-other/day-08/day-08.rkt
@@ -0,0 +1,32 @@
+#lang racket
+
+(require advent-of-code
+         threading)
+
+(struct exits (left right) #:transparent)
+
+(match-define (list raw-directions raw-maze)
+  (~> (fetch-aoc-input (find-session) 2023 8 #:cache #true) (string-split "\n\n")))
+
+(define directions (string->list raw-directions))
+
+(define maze
+  (for/hash ([line (in-list (string-split raw-maze "\n"))])
+    (match (regexp-match #rx"(...) = \\((...), (...)\\)" line)
+      [(list _ name left right) (values name (exits left right))])))
+
+(define (to-next-node start end dirs maze)
+  (for/fold ([current start] [acc 0] #:result acc) ([dir (in-cycle dirs)])
+    #:break (string-suffix? current end)
+    (define node (hash-ref maze current))
+    (case dir
+      [(#\L) (values (exits-left node) (add1 acc))]
+      [(#\R) (values (exits-right node) (add1 acc))])))
+
+;; part 1
+(to-next-node "AAA" "ZZZ" directions maze)
+
+;; part 2
+(for/lists (ns #:result (apply lcm ns))
+           ([start (in-list (hash-keys maze))] #:when (string-suffix? start "A"))
+           (to-next-node start "Z" directions maze))