1 files changed, 0 insertions, 43 deletions
diff --git a/2022/day-21/day-21.rkt b/2022/day-21/day-21.rkt
deleted file mode 100644
index fccd6ad..0000000
--- a/2022/day-21/day-21.rkt
+++ /dev/null
@@ -1,43 +0,0 @@
-#lang racket
-
-(require advent-of-code
-         (only-in relation ->number ->symbol))
-
-(struct monkey (name op) #:transparent)
-(struct op (f first second) #:transparent)
-
-(define (parse-monkey str)
-  (match (string-split str " ")
-    [(list (app (curryr string-trim ":") name) name1 (app ->symbol f) name2)
-     (monkey name (op f name1 name2))]
-    [(list (app (curryr string-trim ":") name) (app ->number int))
-     (monkey name (op 'constant int #f))]))
-
-(define raw-monkeys (port->lines (open-aoc-input (find-session) 2022 21 #:cache #true)))
-
-(define monkey-table
-  (for/hash ([m raw-monkeys] #:do [(match-define (monkey name op) (parse-monkey m))])
-    (values name op)))
-
-;; part 1
-(define (evaluate-monkey m-name [guess #f])
-  (match-define (op f name1 name2)
-    (if (and guess (equal? m-name "humn")) (op 'constant guess #f) (hash-ref monkey-table m-name)))
-  (match f
-    ['constant name1]
-    ['+ (+ (evaluate-monkey name1 guess) (evaluate-monkey name2 guess))]
-    ['- (- (evaluate-monkey name1 guess) (evaluate-monkey name2 guess))]
-    ['* (* (evaluate-monkey name1 guess) (evaluate-monkey name2 guess))]
-    ['/ (/ (evaluate-monkey name1 guess) (evaluate-monkey name2 guess))]))
-
-(evaluate-monkey "root")
-
-;; part 2
-;; since humn only ever appears once, and it's never the divisor in a division operation,
-;; the difference of the branches is linearly proportional to humn
-;; therefore, if we find two points we can calculate the root directly
-(match-define (op _ branch-1 branch-2) (hash-ref monkey-table "root"))
-(define known-side (evaluate-monkey branch-2))
-(define humn-zero (- known-side (evaluate-monkey branch-1 0)))
-(define humn-one (- known-side (evaluate-monkey branch-1 1)))
-(- (/ humn-zero (- humn-one humn-zero)))